WorldWideScience

Sample records for anti-prl cellulose particles

  1. Interfacial properties of green leaf cellulosic particles

    NARCIS (Netherlands)

    Tamayo Tenorio, A.; Gieteling, J.; Nikiforidis, C.V.; Boom, R.M.; Goot, van der A.J.

    2017-01-01

    Cellulosic pulp from sugar beet leaves was fractionated and assessed on its interfacial properties. After pressing leaves to express the juice, the press cake was washed at alkaline pH (pH 9) to remove residual protein, dried, milled and air classified. The obtained cellulosic particles mainly

  2. Reactive Liftoff of Crystalline Cellulose Particles.

    Science.gov (United States)

    Teixeira, Andrew R; Krumm, Christoph; Vinter, Katherine P; Paulsen, Alex D; Zhu, Cheng; Maduskar, Saurabh; Joseph, Kristeen E; Greco, Katharine; Stelatto, Michael; Davis, Eric; Vincent, Brendon; Hermann, Richard; Suszynski, Wieslaw; Schmidt, Lanny D; Fan, Wei; Rothstein, Jonathan P; Dauenhauer, Paul J

    2015-06-09

    The condition of heat transfer to lignocellulosic biomass particles during thermal processing at high temperature (>400 °C) dramatically alters the yield and quality of renewable energy and fuels. In this work, crystalline cellulose particles were discovered to lift off heated surfaces by high speed photography similar to the Leidenfrost effect in hot, volatile liquids. Order of magnitude variation in heat transfer rates and cellulose particle lifetimes was observed as intermediate liquid cellulose droplets transitioned from low temperature wetting (500-600 °C) to fully de-wetted, skittering droplets on polished surfaces (>700 °C). Introduction of macroporosity to the heated surface was shown to completely inhibit the cellulose Leidenfrost effect, providing a tunable design parameter to control particle heat transfer rates in industrial biomass reactors.

  3. Dual morphology (fibres and particles) cellulosic filler for WPC materials

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Marco, E-mail: marco.valente@uniroma1.it; Tirillò, Jacopo; Quitadamo, Alessia, E-mail: alessia.quitadamo@uniroma1.it [University of Rome La Sapienza Dep. of Chemical and Material Engineering (Italy); Santulli, Carlo [University of Camerino, School of Architecture and Design (Italy)

    2016-05-18

    Wood-plastic composites (WPC) were fabricated by using a polyethylene (PE) matrix and filling it with wood flour in the amount of 30 wt.%, and compared with the same composites with further amount of 10 wt.% of cellulosic recycled fibres added. The materials were produced by turbomixing and subsequent moulding under pressure. Mechanical properties of both WPC and WPC with cellulosic recycled fibres were evaluated through mechanical and physical-chemical tests. Tensile tests clarified that a moderate reduction is strength is observed with the bare introduction of wood flour with respect to the neat PE matrix, whilst some recovery is offered by the addition of recycled cellulose fibres. Even more promisingly, the elastic modulus of PE matrix is substantially improved by the addition of wood flour (around 8% on average) and much more so with the further addition of recycled cellulose (around 20% on average). The fracture surfaces from the tensile test were analysed by scanning electron microscope (SEM) indicating a reduction in microporosity as an effect of added cellulose. The water absorption test and the hardness measure (Shore D) were also performed. SEM analysis underlined the weak interface between both wood particle and cellulosic recycled fibres and matrix. The water absorption test showed a higher mass variation for pure WPC than WPC with cellulosic recycled fibres. The hardness measurement showed that the presence of cellulosic recycled fibres improves both superficial hardness of the composite and temperature resistance.

  4. Dual morphology (fibres and particles) cellulosic filler for WPC materials

    Science.gov (United States)

    Valente, Marco; Tirillò, Jacopo; Quitadamo, Alessia; Santulli, Carlo

    2016-05-01

    Wood-plastic composites (WPC) were fabricated by using a polyethylene (PE) matrix and filling it with wood flour in the amount of 30 wt.%, and compared with the same composites with further amount of 10 wt.% of cellulosic recycled fibres added. The materials were produced by turbomixing and subsequent moulding under pressure. Mechanical properties of both WPC and WPC with cellulosic recycled fibres were evaluated through mechanical and physical-chemical tests. Tensile tests clarified that a moderate reduction is strength is observed with the bare introduction of wood flour with respect to the neat PE matrix, whilst some recovery is offered by the addition of recycled cellulose fibres. Even more promisingly, the elastic modulus of PE matrix is substantially improved by the addition of wood flour (around 8% on average) and much more so with the further addition of recycled cellulose (around 20% on average). The fracture surfaces from the tensile test were analysed by scanning electron microscope (SEM) indicating a reduction in microporosity as an effect of added cellulose. The water absorption test and the hardness measure (Shore D) were also performed. SEM analysis underlined the weak interface between both wood particle and cellulosic recycled fibres and matrix. The water absorption test showed a higher mass variation for pure WPC than WPC with cellulosic recycled fibres. The hardness measurement showed that the presence of cellulosic recycled fibres improves both superficial hardness of the composite and temperature resistance.

  5. Experimental determination of alpha particle threshold detection in cellulose nitrate

    International Nuclear Information System (INIS)

    Knoefell, T.M.J.

    1978-01-01

    LR 115, type II, Kodak-Pathe cellulose nitrate pellicles were irradiated perpendicularly with monoenergetic alpha bemas in the energy range 2,5-5,5 Mev. The alpha particle beams were produced by an intense Am 241 source using Argon as energy attenuating. After irradiations, samples were etched with NaOH solutions without agitation at 60 0 C, by different time periods varying from 15 minutes to 3,5 hours. Measurements of density and track diameter were done using optical microscopy. The sample compositions were done by CHN method of combustion gas analysis showing good agreement with the composition of cellulose trinitrate. From detection threshold and from obtained results, the development of latent tracks only occur for alpha particles with stopping power superior to 0,87 +- 0,06 MeV.cm -2 .mg -1 , was verified. (M.C.K.) [pt

  6. Bond scission cross sections for alpha-particles in cellulose nitrate (LR115)

    CERN Document Server

    Barillon, R; Chambaudet, A; Katz, R; Stoquert, J P; Pape, A

    1999-01-01

    Chemical damage created by alpha-particles in cellulose nitrate (LR115) have been studied by infrared spectroscopy. This technique enables identifying the sensitive bonds and giving an order of magnitude of their scission cross sections for given alpha-particle energies. The high cross sections observed suggest a new description of the track etch velocity in this material.

  7. The Effect of Dust Particles on Cellulose Degradation

    Czech Academy of Sciences Publication Activity Database

    Bartl, B.; Mašková, Ludmila; Paulusová, H.; Smolík, Jiří; Bartlová, L.; Vodička, Petr

    2016-01-01

    Roč. 61, č. 4 (2016), s. 203-208 ISSN 0039-3630 R&D Projects: GA MK DF11P01OVV020 Keywords : cellulose * paper * dust Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.578, year: 2016

  8. Interrelationships between cellulase activity and cellulose particle morphology

    DEFF Research Database (Denmark)

    Olsen, Johan Pelck; Donohoe, Bryon S.; Borch, Kim

    2016-01-01

    It is well documented that the enzymatic hydrolysis of cellulose follows a reaction pattern where an initial phase of relatively high activity is followed by a gradual slow-down over the entire course of the reaction. This phenomenon is not readily explained by conventional factors like substrate...

  9. Comparison of Influenza Virus Particle Purification Using Magnetic Sulfated Cellulose Particles with an Established Centrifugation Method for Analytics.

    Science.gov (United States)

    Serve, Anja; Pieler, Michael Martin; Benndorf, Dirk; Rapp, Erdmann; Wolff, Michael Werner; Reichl, Udo

    2015-11-03

    A method for the purification of influenza virus particles using novel magnetic sulfated cellulose particles is presented and compared to an established centrifugation method for analytics. Therefore, purified influenza A virus particles from adherent and suspension MDCK host cell lines were characterized on the protein level with mass spectrometry to compare the viral and residual host cell proteins. Both methods allowed one to identify all 10 influenza A virus proteins, including low-abundance proteins like the matrix protein 2 and nonstructural protein 1, with a similar impurity level of host cell proteins. Compared to the centrifugation method, use of the novel magnetic sulfated cellulose particles reduced the influenza A virus particle purification time from 3.5 h to 30 min before mass spectrometry analysis.

  10. Modelling the fast pyrolysis of cellulosic particles in fluid-bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Di Colomba Di Blasi, C. [Universita degli Studi di Napoli ' ' Federico II' ' (Italy). Dip. di Ingegneria Chimica

    2000-07-01

    A mathematical model for intra-particle transport phenomena and chemical reactions is coupled with an external heat transfer model taking into account fluid-bed hydrodynamics, to predict the fast pyrolysis characteristics of cellulose fuels. Good agreement is obtained between predicted and measured product yields as functions of the reactor temperature. For practical applications aimed at liquid fuel production, particle size and external temperatures greatly affect the average particle heating rate (values roughly comprised between 300 and 1 K/s), whereas the actual degradation temperature vary in a narrow range (600-725 K). Consequently, variations in the conversion time are significantly larger than in product distribution and yields. Finally, comparisons are made with the Ranz-Marshall correlation and the limit case of infinitely fast external heat transfer rates. (Author).

  11. Levoglucosan, a tracer for cellulose in biomass burning and atmospheric particles

    Science.gov (United States)

    Simoneit, B. R. T.; Schauer, J. J.; Nolte, C. G.; Oros, D. R.; Elias, V. O.; Fraser, M. P.; Rogge, W. F.; Cass, G. R.

    The major organic components of smoke particles from biomass burning are monosaccharide derivatives from the breakdown of cellulose, accompanied by generally lesser amounts of straight-chain, aliphatic and oxygenated compounds and terpenoids from vegetation waxes, resins/gums, and other biopolymers. Levoglucosan and the related degradation products from cellulose can be utilized as specific and general indicator compounds for the presence of emissions from biomass burning in samples of atmospheric fine particulate matter. This enables the potential tracking of such emissions on a global basis. There are other compounds (e.g. amyrones, friedelin, dehydroabietic acid, and thermal derivatives from terpenoids and from lignin—syringaldehyde, vanillin, syringic acid, vanillic acid), which are additional key indicators in smoke from burning of biomass specific to the type of biomass fuel. The monosaccharide derivatives (e.g. levoglucosan) are proposed as specific indicators for cellulose in biomass burning emissions. Levoglucosan is emitted at such high concentrations that it can be detected at considerable distances from the original combustion source.

  12. Combination of microsized mineral particles and rosin as a basis for converting cellulosic fibers into "sticky" superhydrophobic paper.

    Science.gov (United States)

    Yu, Xiaoyan; Bian, Peiwen; Xue, Yang; Qian, Xueren; Yu, Haipeng; Chen, Wenshuai; Hu, Xiaohai; Wang, Peng; Wu, Dong; Duan, Qinghui; Li, Limei; Shen, Jing; Ni, Yonghao

    2017-10-15

    The unique features of cellulosic paper including flexibility, biodegradability, and low cost enables it as a versatile, sustainable biomaterial for promising applications. In the paper industry, microsized mineral particles are widely used in the production of printing/writing paper grades, while rosin derived from trees is the earliest internal sizing agent for paper hydrophobication. On the basis of existing commercial practices associated with the use of mineral particles and rosin in paper production, we present a process concept of converting cellulosic fibers (paper-grade pulp) into "sticky" superhydrophobic paper involving the use of microsized mineral particles and rosin (a tree-derived natural product, mainly a mixture of resin acids, especially abietic acid with chemical formula of C 19 H 29 COOH). Internal filling of cellulosic networks with mineral particles was basically used to hold out the mineral particles added at the surface, and the delicate integration of wet-end/surface applications of mineral particles with paper surface engineering with rosin/alum led to the development of "sticky" superhydrophobicity, i.e., ultrahigh water-repellency and strong adhesion to water. This proposed concept may provide valuable implications for expanding the use of paper-based products to unconventional applications, e.g., ultrahigh-performance ink jet printing paper for mitigating the "coffee-ring effect" and paper-based microfluidic devices for biomedical testing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Morphology and mechanical properties of poly(β-hydroxybutyrate)/poly(ε-caprolactone) blends controlled with cellulosic particles.

    Science.gov (United States)

    Chen, Jianxiang; Wang, Yuankun; Yin, Zeren; Tam, Kam C; Wu, Defeng

    2017-10-15

    The rigid microcrystalline cellulose (MCC) particles and semi-rigid ethyl cellulose (EC) were used to control phase morphology and mechanical properties of immiscible poly(β-hydroxybutyrate) (PHB)/poly(ε-caprolactone) (PCL) blends. The interfacial properties were evaluated by the fiber retraction and contact angle methods MCC is incompatible with PHB and PCL, and dispersed independently in the two polymer phases in their blends. However, EC is more compatible with the two polymers, with a higher affinity for PCL. And EC prefers locating in PCL domains and at the phase interface. Selective localization of MCC and EC affects the mechanical properties and phase structure of PHB/PCL blends strongly. For the co-continuous samples, the presence of MCC and EC improves both the tensile and impact strengths. For the 'sea-island' ones, however, the changes of strengths depends strongly on the phase adhesion. This work will help focus efforts on moderating structure and properties of immiscible polymer blends using cellulose particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effect of particle shape on powder flowability of microcrystalline cellulose as determined using the vibration shear tube method.

    Science.gov (United States)

    Horio, Takehiko; Yasuda, Masatoshi; Matsusaka, Shuji

    2014-10-01

    Powder flowability of microcrystalline cellulose particles having different particle shapes, whose aspect ratios ranged from 1.8 to 6.4, was measured using the vibration shear tube method. Particles lubricated with magnesium stearate were also investigated in order to evaluate the effect of surface modification on powder flowability. Particles were discharged through a narrow gap between a vibrating tube edge and a flat bottom surface, where each particle experienced high shear forces, thus, overcoming adhesion and friction forces. Vibration amplitude was increased at a constant rate during measurement and the masses of the discharged particles were measured at consistent time intervals. Flowability profiles, i.e., the relationships between the mass flow rates of the discharged particles and their vibration accelerations, were obtained from these measurements. Critical vibration accelerations and characteristic mass flow rates were then determined from flowability profiles in order to evaluate static and dynamic friction properties. The results were compared with those obtained using conventional methods. It was found that angle of repose and compressibility were related to static and dynamic friction properties. Furthermore, it was found that particle aspect ratio more significantly affects powder flowability than does lubrication with magnesium stearate. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Effect of particle Alignment on mechanical properties of neat cellulose nanocrystal films

    Science.gov (United States)

    Alexander B. Reising; Robert J. Moon; Jeffrey P. Youngblood

    2012-01-01

    Shear-based film casting methods were used to cast neat films from wood-based cellulose nanocrystal (CNC) suspensions. The degree of CNC alignment in dried films was characterized using the Hermans order parameter (S), and the film elastic modulus (E), ultimate tensile strength (σf ), elongation at failure (εf...

  16. Mathematical modeling of flow and kinetics in a reactor for dilute-Acid hydrolysis of cellulose particles: a mixture flow approach.

    Science.gov (United States)

    Zahrai, Sima; Wikström, Gunilla

    2007-02-01

    A mathematical model to simulate the dilute-acid hydrolysis process of cellulose particles is presented. In this model, the mass is treated as a mixture of different components. A test case is considered for which transport equations for components are developed and solved together with the momentum equation for the fluid flow. To solve the model equations, a commercially available flow solver was used. All input data were taken from previously published works. For the small static mixer considered as test geometry, the result, in terms of the conversion of the cellulose particles, was reasonable. With input parameters that are relevant to a plant-size reactor, the model can be used to predict the conversion of both cellulose and hemicellulose particles.

  17. NTP Toxicity Study Report on the atmospheric characterization, particle size, chemical composition, and workplace exposure assessment of cellulose insulation (CELLULOSEINS).

    Science.gov (United States)

    Morgan, Daniel L

    2006-08-01

    Cellulose insulation (CI) is a type of thermal insulation produced primarily from recycled newspapers. The newspapers are shredded, milled, and treated with fire-retardant chemicals. The blowing process for installing CI generates a significant quantity of airborne material that presents a potential inhalation hazard to workers. CI was selected for study based upon the high production volume, the potential for widespread human exposure, and a lack of toxicity data; insufficient information was available to determine whether inhalation studies in laboratory animals were technically feasible or necessary. Studies were conducted to characterize the chemical and physical properties of CI aerosols, to evaluate the potential acute pulmonary toxicity of CI, and to assess occupational exposure of CI installers. Workplace exposure assessments were conducted in collaboration with the National Institute for Occupational Safety and Health (NIOSH, 2001). Chemical analyses were performed on samples of bulk CI from four major United States manufacturers. All samples of the bulk CI were found to contain primarily amorphous cellulose (60% to 65%) with a smaller crystalline component (35% to 40%). The crystalline phase was primarily native cellulose (75% to 85%) with a minor amount of cellulose nitrate (15% to 25%). Elemental analyses of acid digests of CI materials indicated that the major components (>0.1% by weight) included aluminum, boron, calcium, sodium, and sulfur. An acid-insoluble residue present in all four materials (3% to 5% of original sample weight) was found to consist primarily of aluminum silicate hydroxide (kaolinite; approximately 85%) with minor amounts (generation system was designed to separate CI particles based upon aerodynamic size and to simulate the process used during CI installation at work sites. Less than 0.1% of each of the CI samples was collected as the small respirable particle fraction. The mean equivalent diameter of respirable particles ranged

  18. Cellulose nanomaterials review: structure, properties and nanocomposites

    Science.gov (United States)

    Robert J. Moon; Ashlie Martini; John Nairn; John Simonsen; Jeff Youngblood

    2011-01-01

    This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The...

  19. Overview of Cellulose Nanomaterials, Their Capabilities and Applications

    Science.gov (United States)

    Robert J. Moon; Gregory T. Schueneman; John Simonsen

    2016-01-01

    Cellulose nanomaterials (CNs) are a new class of cellulose particles with properties and functionalities distinct from molecular cellulose and wood pulp, and as a result, they are being developed for applications that were once thought impossible for cellulosic materials. Momentum is growing in CN research and development, and commercialization in this field is...

  20. Effect of cellulose nanocrystals (CNC) particle morphology on dispersion and rheological and mechanical properties of polypropylene/CNC nanocomposites.

    Science.gov (United States)

    Khoshkava, Vahid; Kamal, Musa R

    2014-06-11

    Polypropylene (PP) nanocomposites containing spray-dried cellulose nanocrystals (CNC), freeze-dried CNC, and spray-freeze-dried CNC (CNCSFD) were prepared via melt mixing in an internal batch mixer. Polarized light, scanning electron, and atomic force microscopy showed significantly better dispersion of CNCSFD in PP/CNC nanocomposites compared with the spray-dried and freeze-dried CNCs. Rheological measurements, including linear and nonlinear viscoelastic tests, were performed on PP/CNC samples. The microscopy results were supported by small-amplitude oscillatory shear tests, which showed substantial rises in the magnitudes of key rheological parameters of PP samples containing CNCSFD. Steady-shear results revealed a strong shear thinning behavior of PP samples containing CNCSFD. Moreover, PP melts containing CNCSFD exhibited a yield stress. The magnitude of the yield stress and the degree of shear thinning behavior increased with CNCSFD concentration. It was found that CNCSFD agglomerates with a weblike structure were more effective in modifying the rheological properties. This effect was attributed to better dispersion of the agglomerates with the weblike structure. Dynamic mechanical analysis showed considerable improvement in the modulus of samples containing CNCSFD agglomerates. The percolation mechanical model with modified volume percolation threshold and filler network strength values and the Halpin-Kardos model were used to fit the experimental results.

  1. Cellulose is not just cellulose

    DEFF Research Database (Denmark)

    Hidayat, Budi Juliman; Felby, Claus; Johansen, Katja Salomon

    2012-01-01

    Most secondary plant cell walls contain irregular regions known as dislocations or slip planes. Under industrial biorefining conditions dislocations have recently been shown to play a key role during the initial phase of the enzymatic hydrolysis of cellulose in plant cell walls. In this review we...... chart previous publications that have discussed the structure of dislocations and their susceptibility to hydrolysis. The supramolecular structure of cellulose in dislocations is still unknown. However, it has been shown that cellulose microfibrils continue through dislocations, i.e. dislocations...... are not regions where free cellulose ends are more abundant than in the bulk cell wall. In more severe cases cracks between fibrils form at dislocations and it is possible that the increased accessibility that these cracks give is the reason why hydrolysis of cellulose starts at these locations. If acid...

  2. Methane fermentation of cellulose and ligno-cellulosic materials

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, J.S.; Villermaux, S.; Prost, C. (Laboratoire des Sciences du Genie Chimique, 54 - Nancy (France))

    1985-01-01

    Study of the methane fermentation of two simple substrates i.e. pure cellulose and oat straw. Experiments have been carried out in laboratory fermentors with several initial cellulose concentrations and different straw particle sizes. The results show the effect of adding nutrients and enriched seedings with pure cellulolytic or methanogenic bacteria. In each case, the rate limiting step is defined and the degradation kinetics of the two substrates are compared.

  3. Development Of Radioimmunoassay For Prolactin HORMONE Using Solid Phase Magnetic Particles

    International Nuclear Information System (INIS)

    SHAFIK, H.M.; MEHANY, N.L.

    2009-01-01

    The preparation and development of primary reagents of prolactin (PRL) radioimmunoassay (RIA) technique using solid phase magnetic particles with low cost is considered to be the main objective of the present study. The production of polyclonal antibodies was undertaken by immunizing four female New-Zealand rabbits through primary injection and four booster doses subcutaneously. The preparation of 125 I-prolactin radiotracer was carried out using chloramine-T. The preparation of standard prolactin was undertaken by preparing stock standard solution of prolactin and diluted with assay buffer. Activation and coupling of low magnetizable particles with the purified anti-PRL was carried out. Optimization and validation of the assay were carried out. The results obtained provide a highly sensitive, specific and accurate RIA system of PRL. In conclusion, this assay could be used in diagnosis of galactorrhea, prolactinoma, visual impairment and diagnosis of infertility in males and females.

  4. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1977-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artificial test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiography by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (Auth.)

  5. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1976-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artifical test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiographs by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (orig.) [de

  6. Regulating Drug Release Behavior and Kinetics from Matrix Tablets Based on Fine Particle-Sized Ethyl Cellulose Ether Derivatives: An In Vitro and In Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Kifayat Ullah Shah

    2012-01-01

    Full Text Available The design and fabrication of sustained/controlled release dosage forms, employing new excipients capable of extending/controlling the release of drugs from the dosage forms over prolonged periods, has worked well in achieving optimally enhanced therapeutic levels of the drugs. In this sense, the objective of this study was to investigate the suitability of selected cellulose ether derivatives for use in direct compression (DC and as efficient drug release controlling agents. Controlled release matrix tablets of ciprofloxacin were prepared at different drug-to-polymer (D : P ratios by direct compression using a fine particle sized ethylcellulose ether derivative (ETHOCEL Standard Premium 7FP as rate controlling polymer. The tablets obtained were evaluated for various physico-chemical characteristics and in-vitro drug release studies were conducted in phosphate buffer (pH 7.4 using PharmaTest dissolution apparatus at constant temperature of 37∘C±0.1. Similarity factor 2 was employed to the release profiles of test formulations and were compared with marketed ciprofloxacin conventional tablets. Drug release mechanism and the kinetics involved were investigated by fitting the release profile data to various kinetic models. It was found that with increasing the proportion of ethylcellulose ether derivative in the matrix, the drug release was significantly extended up to 24 hours. The tablets exhibited zero order or nearly zero order drug transport mechanism. In vivo drug release performance of the developed controlled release tablets and reference conventional tablets containing ciprofloxacin were determined in rabbit serum according to randomized two-way crossover study design using High Performance Liquid Chromatography. Several bioavailability parameters of both the test tablets and conventional tablets including max, max and AUC0- were compared which showed an optimized max and max (<0.05. A good correlation was obtained between in vitro

  7. Cellulose Insulation

    Science.gov (United States)

    1980-01-01

    Fire retardant cellulose insulation is produced by shredding old newspapers and treating them with a combination of chemicals. Insulating material is blown into walls and attics to form a fiber layer which blocks the flow of air. All-Weather Insulation's founders asked NASA/UK-TAP to help. They wanted to know what chemicals added to newspaper would produce an insulating material capable of meeting federal specifications. TAP researched the query and furnished extensive information. The information contributed to successful development of the product and helped launch a small business enterprise which is now growing rapidly.

  8. Cellulose Perversions

    Directory of Open Access Journals (Sweden)

    Maria H. Godinho

    2013-03-01

    Full Text Available Cellulose micro/nano-fibers can be produced by electrospinning from liquid crystalline solutions. Scanning electron microscopy (SEM, as well as atomic force microscopy (AFM and polarizing optical microscopy (POM measurements showed that cellulose-based electrospun fibers can curl and twist, due to the presence of an off-core line defect disclination, which was present when the fibers were prepared. This permits the mimicking of the shapes found in many systems in the living world, e.g., the tendrils of climbing plants, three to four orders of magnitude larger. In this work, we address the mechanism that is behind the spirals’ and helices’ appearance by recording the trajectories of the fibers toward diverse electrospinning targets. The intrinsic curvature of the system occurs via asymmetric contraction of an internal disclination line, which generates different shrinkages of the material along the fiber. The completely different instabilities observed for isotropic and anisotropic electrospun solutions at the exit of the needle seem to corroborate the hypothesis that the intrinsic curvature of the material is acquired during liquid crystalline sample processing inside the needle. The existence of perversions, which joins left and right helices, is also investigated by using suspended, as well as flat, targets. Possible routes of application inspired from the living world are addressed.

  9. Compósitos de borracha natural ou policloropreno e celulose II: influência do tamanho de partícula Natural rubber or chloroprene rubber and cellulose II composites: influence of particle size

    Directory of Open Access Journals (Sweden)

    Bruno de A. Napolitano

    2004-01-01

    Full Text Available O objetivo deste trabalho foi o desenvolvimento de compósitos claros com propriedades de interesse tecnológico utilizando elastômeros com diferentes polaridades. Para que este objetivo fosse atingido, celulose II em pó foi usada como carga, em borracha natural (NR ou policloropreno (CR. A celulose II foi obtida por coagulação da solução de xantato de celulose em meio ácido, sob agitação constante e à temperatura ambiente, constituindo uma nova forma de obtenção deste tipo de carga. Compósitos com 10 phr de celulose II com NR e CR, respectivamente, foram desenvolvidos tendo como variável o tamanho de partícula da carga. As propriedades mecânicas e os aspectos microscópicos dos diferentes compósitos foram avaliados e comparados com aqueles das formulações sem carga. Os resultados permitiram identificar o compósito como o de melhor resultado, influenciado pela polaridade da matriz elastomérica e pelo tamanho de partícula da carga, conseqüência das condições de moagem usadas.The aim of this work was to develop light composites with properties of technological interest by using elastomers of different polarities. This was achieved by employing cellulose II, in the powder form, as filler in natural rubber (NR and chloroprene (CR. Cellulose II was obtained by coagulation of cellulose xanthate solution, in acid medium, under stirring and at room temperature, which represents, to our knowledge, a new way of obtaining this type of filler. Composites with 10phr of cellulose II and NR or CR were prepared having the particle size as variable. The mechanical properties and the microscopic aspect of the different composites were evaluated and compared with compounds without filler. The results indicated best results for the CR composite, influenced by the polarity of the elastomeric matrix and by the particle size, as a consequence of the milling conditions of the filler used.

  10. Cellulosic ethanol

    DEFF Research Database (Denmark)

    Lindedam, Jane; Bruun, Sander; Jørgensen, Henning

    2010-01-01

    Background Variations in sugar yield due to genotypic qualities of feedstock are largely undescribed for pilot-scale ethanol processing. Our objectives were to compare glucose and xylose yield (conversion and total sugar yield) from straw of five winter wheat cultivars at three enzyme loadings (2...... yields than coarse particles. The amount of coarse particles from the cultivar with lowest sugar yield was negatively correlated with sugar conversion. Conclusions We conclude that genetic differences in sugar yield and response to enzyme loading exist for wheat straw at pilot scale, depending...

  11. A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods.

    Science.gov (United States)

    Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

    2017-08-01

    This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80min or 120min (BMW 80 , BMW 120 ) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW 120 was achieved, which was three times as high as the conversion of BMW 80 . The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72g/L and 88.16g/L lignosulfonate concentration, respectively, were harvested from HR 80 and HR 120 , and 42.6±0.5% lignin were removed. The subsequent solid residuals were purified to produce cellulose and then this material was acid-hydrolyzed to produce cellulose nanocrystals. The BMW 120 maintained smaller particle size and aspect ratio during each step of during the multiple processes, while the average aspect ratio of its cellulose nanocrystals was larger. The crystallinity of both materials increased with each step of wet processing, reaching to 74% for the cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. investigation of eco-friendly cellulosic nanoparticles potential as ...

    African Journals Online (AJOL)

    HOD

    Keywords: Mechanical Properties; Cellulosic Nanoparticles; Rubber-Matrix Composites; Carbon Black. 1. INTRODUCTION. In recent times .... The fibres of the various biomass were further treated using mixture of 1.5 % H2O2/ 2% ..... of formation of covalent bond when compared with cellulosic particle surface. Previous ...

  13. Characterization of cellulose nanowhiskers

    International Nuclear Information System (INIS)

    Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia

    2015-01-01

    Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

  14. Acoustic Properties of Cellulose

    Science.gov (United States)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-08-01

    Cellulose is the oldest material for thermal insulation in construction field. Thomas Jefferson was the first architect that used the cellulose in his project of the Monticello house (1800). But only after 1945 that the cellulose from newsprint was used across America and northern Europe. In the 70s with the energy crisis it Austria, Czech Republic, Switzerland and Germany began the production of cellulose derived from paper newspapers. It used for both winter and summer thermal insulation, while respecting the environment. In this paper are reported acoustic measurements carried out with the tube of Kundt, with the cellulose melted and with glue with different thicknesses.

  15. Electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  16. Reflection of circularly polarized light and the effect of particle distribution on circular dichroism in evaporation induced self-assembled cellulose nanocrystal thin films

    Science.gov (United States)

    Hewson, D.; Vukusic, P.; Eichhorn, S. J.

    2017-06-01

    Evaporation induced self-assembled (EISA) thin films of cellulose nanocrystals (CNCs) have shown great potential for displaying structural colour across the visible spectrum. They are believed primarily to reflect left handed circularly polarised (LCP) light due to their natural tendency to form structures comprising left handed chirality. Accordingly the fabrication of homogenously coloured CNC thin films is challenging. Deposition of solid material towards the edge of a dried droplet, via the coffee-stain effect, is one such difficulty in achieving homogenous colour across CNC films. These effects are most easily observed in films prepared from droplets where observable reflection of visible light is localised around the edge of the dry film. We report here, the observation of both left and right hand circularly polarised (LCP/RCP) light in reflection from distinct separate regions of CNC EISA thin films and we elucidate how these reflections are dependent on the distribution of CNC material within the EISA thin film. Optical models of reflection are presented which are based on structures revealed using high resolution transmission electron microscopy (TEM) images of film cross sections. We have also employed spectroscopic characterisation techniques to evaluate the distribution of solid CNC material within a selection of CNC EISA thin films and we have correlated this distribution with polarised light spectra collected from each film. We conclude that film regions from which RCP light was reflected were associated with lower CNC concentrations and thicker film regions.

  17. Reflection of circularly polarized light and the effect of particle distribution on circular dichroism in evaporation induced self-assembled cellulose nanocrystal thin films

    Directory of Open Access Journals (Sweden)

    D. Hewson

    2017-06-01

    Full Text Available Evaporation induced self-assembled (EISA thin films of cellulose nanocrystals (CNCs have shown great potential for displaying structural colour across the visible spectrum. They are believed primarily to reflect left handed circularly polarised (LCP light due to their natural tendency to form structures comprising left handed chirality. Accordingly the fabrication of homogenously coloured CNC thin films is challenging. Deposition of solid material towards the edge of a dried droplet, via the coffee-stain effect, is one such difficulty in achieving homogenous colour across CNC films. These effects are most easily observed in films prepared from droplets where observable reflection of visible light is localised around the edge of the dry film. We report here, the observation of both left and right hand circularly polarised (LCP/RCP light in reflection from distinct separate regions of CNC EISA thin films and we elucidate how these reflections are dependent on the distribution of CNC material within the EISA thin film. Optical models of reflection are presented which are based on structures revealed using high resolution transmission electron microscopy (TEM images of film cross sections. We have also employed spectroscopic characterisation techniques to evaluate the distribution of solid CNC material within a selection of CNC EISA thin films and we have correlated this distribution with polarised light spectra collected from each film. We conclude that film regions from which RCP light was reflected were associated with lower CNC concentrations and thicker film regions.

  18. How recombinant swollenin from Kluyveromyces lactis affects cellulosic substrates and accelerates their hydrolysis

    Directory of Open Access Journals (Sweden)

    Jäger Gernot

    2011-09-01

    Full Text Available Abstract Background In order to generate biofuels, insoluble cellulosic substrates are pretreated and subsequently hydrolyzed with cellulases. One way to pretreat cellulose in a safe and environmentally friendly manner is to apply, under mild conditions, non-hydrolyzing proteins such as swollenin - naturally produced in low yields by the fungus Trichoderma reesei. To yield sufficient swollenin for industrial applications, the first aim of this study is to present a new way of producing recombinant swollenin. The main objective is to show how swollenin quantitatively affects relevant physical properties of cellulosic substrates and how it affects subsequent hydrolysis. Results After expression in the yeast Kluyveromyces lactis, the resulting swollenin was purified. The adsorption parameters of the recombinant swollenin onto cellulose were quantified for the first time and were comparable to those of individual cellulases from T. reesei. Four different insoluble cellulosic substrates were then pretreated with swollenin. At first, it could be qualitatively shown by macroscopic evaluation and microscopy that swollenin caused deagglomeration of bigger cellulose agglomerates as well as dispersion of cellulose microfibrils (amorphogenesis. Afterwards, the effects of swollenin on cellulose particle size, maximum cellulase adsorption and cellulose crystallinity were quantified. The pretreatment with swollenin resulted in a significant decrease in particle size of the cellulosic substrates as well as in their crystallinity, thereby substantially increasing maximum cellulase adsorption onto these substrates. Subsequently, the pretreated cellulosic substrates were hydrolyzed with cellulases. Here, pretreatment of cellulosic substrates with swollenin, even in non-saturating concentrations, significantly accelerated the hydrolysis. By correlating particle size and crystallinity of the cellulosic substrates with initial hydrolysis rates, it could be shown that

  19. Investigation of the physico-mechanical properties of electrospun PVDF/cellulose nanofibers.

    OpenAIRE

    Issa, A.A.; Al-Maadeed, M.; Luyt, A.S.; Mrlik, M.; Hassan, M.K.

    2016-01-01

    The electro-activity and mechanical properties of PVDF depends mainly on the b-phase content and degree of crystallinity. In this study, cellulose fibers were used to improve these characteristics. This could be achieved because the hydroxyl groups on cellulose would force the fluorine atoms in PVDF to be in the trans-conformation, and the cellulose particles could act as nucleation centers. Electrospinning was used to prepare the PVDF/cellulose (nano)fibrous films, and this improved the tota...

  20. Synthesis and characterization of amorphous cellulose from triacetate of cellulose

    International Nuclear Information System (INIS)

    Vega-Baudrit, Jose; Sibaja, Maria; Nikolaeva, Svetlana; Rivera A, Andrea

    2014-01-01

    It was carried-out a study for the synthesis and characterization of amorphous cellulose starting from cellulose triacetate. X-rays diffraction was used in order to obtain the cellulose crystallinity degree, also infrared spectroscopy FTIR was used. (author)

  1. Cellulose-silica aerogels.

    Science.gov (United States)

    Demilecamps, Arnaud; Beauger, Christian; Hildenbrand, Claudia; Rigacci, Arnaud; Budtova, Tatiana

    2015-05-20

    Aerogels based on interpenetrated cellulose-silica networks were prepared and characterised. Wet coagulated cellulose was impregnated with silica phase, polyethoxydisiloxane, using two methods: (i) molecular diffusion and (ii) forced flow induced by pressure difference. The latter allowed an enormous decrease in the impregnation times, by almost three orders of magnitude, for a sample with the same geometry. In both cases, nanostructured silica gel was in situ formed inside cellulose matrix. Nitrogen adsorption analysis revealed an almost threefold increase in pores specific surface area, from cellulose aerogel alone to organic-inorganic composite. Morphology, thermal conductivity and mechanical properties under uniaxial compression were investigated. Thermal conductivity of composite aerogels was lower than that of cellulose aerogel due to the formation of superinsulating mesoporous silica inside cellulose pores. Furthermore, composite aerogels were stiffer than each of reference aerogels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Internally plasticised cellulose polymers

    International Nuclear Information System (INIS)

    Burnup, M.; Hayes, G.F.; Fydelor, P.J.

    1981-01-01

    Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

  3. Preparation of silver nano-particles immobilized onto chitin nano-crystals and their application to cellulose paper for imparting antimicrobial activity.

    Science.gov (United States)

    Li, Zhihan; Zhang, Ming; Cheng, Dong; Yang, Rendang

    2016-10-20

    Immobilized silver nano-particles (Ag NPs) possess excellent antimicrobial properties due to their unique surface characteristics. In this paper, immobilized silver nano-particles were synthesized in the presence of chitin nano-crystals (CNC) based on the Tollens mechanism (reduction of silver ion by aldehydes in the chitosan oligosaccharides (COS)) under microwave-assisted conditions. The prepared Ag NPs-loaded CNC nano-composites were then applied onto the paper surface via coating for the preparation of antibacterial paper. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) results confirmed that the Ag NPs were immobilized onto the CNC. The transmission electron microscope (TEM) and scanning electron microscopy (SEM) results further revealed that the spherical Ag NPs (5-12nm) were well dispersed on the surface of CNC. The coated paper made from the Ag NPs-loaded CNC nano-composites exhibited a high effectiveness of the antibacterial activity against E. coli or S. aureus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Surface structure, crystallographic and ice-nucleating properties of cellulose

    Science.gov (United States)

    Hiranuma, Naruki; Möhler, Ottmar; Kiselev, Alexei; Saathoff, Harald; Weidler, Peter; Shutthanandan, Shuttha; Kulkarni, Gourihar; Jantsch, Evelyn; Koop, Thomas

    2015-04-01

    Increasing evidence of the high diversity and efficient freezing ability of biological ice-nucleating particles is driving a reevaluation of their impact upon climate. Despite their potential importance, little is known about their atmospheric abundance and ice nucleation efficiency, especially non-proteinaceous ones, in comparison to non-biological materials (e.g., mineral dust). Recently, microcrystalline cellulose (MCC; non-proteinaceous plant structural polymer) has been identified as a potential biological ice-nucleating particle. However, it is still uncertain if the ice-nucleating activity is specific to the MCC structure or generally relevant to all cellulose materials, such that the results of MCC can be representatively scaled up to the total cellulose content in the atmosphere to address its role in clouds and the climate system. Here we use the helium ion microscopy (HIM) imaging and the X-ray diffraction (XRD) technique to characterize the nanoscale surface structure and crystalline properties of the two different types of cellulose (MCC and fibrous cellulose extracted from natural wood pulp) as model proxies for atmospheric cellulose particles and to assess their potential accessibility for water molecules. To complement these structural characterizations, we also present the results of immersion freezing experiments using the cold stage-based droplet freezing BINARY (Bielefeld Ice Nucleation ARaY) technique. The HIM results suggest that both cellulose types have a complex porous morphology with capillary spaces between the nanoscale fibrils over the microfiber surface. These surface structures may make cellulose accessible to water. The XRD results suggest that the structural properties of both cellulose materials are in agreement (i.e., P21 space group; a=7.96 Å, b=8.35 Å, c=10.28 Å) and comparable to the crystallographic properties of general monoclinic cellulose (i.e., Cellulose Iβ). The results obtained from the BINARY measurements suggest

  5. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  6. Fulton Cellulosic Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Sumait, Necy [BlueFire Ethanol, Irvine, CA (United States); Cuzens, John [BlueFire Ethanol, Irvine, CA (United States); Klann, Richard [BlueFire Ethanol, Irvine, CA (United States)

    2015-07-24

    Final report on work performed by BlueFire on the deployment of acid hydrolysis technology to convert cellulosic waste materials into renewable fuels, power and chemicals in a production facility to be located in Fulton, Mississippi.

  7. Photomobility and photohealing of cellulose-based hybrids

    Science.gov (United States)

    Ulasevich, Sviatlana A.; Melnyk, Inga; Andreeva, Daria V.; Möhwald, Helmuth; Skorb, Ekaterina V.

    2017-08-01

    In an effort to control the electronic and mechanical interaction between an inorganic surface and a defined polymeric coating, we present a new and easy method of a cellulose-based hybrid formation. We used Schweizer's reagent, a specific copper ammonia hydroxide-based solvent for cotton dissolution and found the optimal concentration for the formation of photosensitive uniform cellulose coating on titania, TiO2-cellulose coating and free-standing hybrid. Photomobility, the material mobility induced by light, of a cellulose layer on a titania surface and of a TiO2-cellulose hybrid on a silicon wafer has been studied. This can be used for photohealing, and the most promising system is the one that can be healed with light due to in situ activation of titania nanoparticles assembled on cellulose fibers in a hydrogel. The interfacial contact between titania particles and fiber is important for local transport of electrons and ions, thus the most promising system was obtained by in situ synthesis of titania nanoparticles on cellulose dispersed in Schweizer's reagent. We propose that cellulose coatings on titania surface and free-standing hybrids can be applicable for a wide range of photochemical devices: films for optics, drug delivery systems, and inks for printing of biologically relevant lab-on-chips. Contribution to the Focus Issue Self-assemblies of Inorganic and Organic Nanomaterials edited by Marie-Paule Pileni.

  8. Superhydrophobic cellulose-based bionanocomposite films from Pickering emulsions

    Science.gov (United States)

    Bayer, Ilker S.; Steele, Adam; Martorana, Philip J.; Loth, Eric; Miller, Lance

    2009-04-01

    Inherently superhydrophobic and flexible cellulose-based bionanocomposites were fabricated from solid stabilized (Pickering) emulsions. Emulsions were formed by dispersing cyclosiloxanes in water stabilized by layered silicate particles and were subsequently modified by blending into a zinc oxide nanofluid. The polymer matrix was a blend of cellulose nitrate and fluoroacrylic polymer (Zonyl 8740) precompatibilized in solution. Coatings were spray cast onto aluminum substrates from polymer blends dispersed in modified Pickering emulsions. No postsurface treatment was required to induce superhydrophobicity. Effect of antiseptic additives on bionanocomposite superhydrophobicity is also discussed. Replacing cellulose nitrate with commercial liquid bandage solutions produced identical superhydrophobic coatings.

  9. Provision of micro-nano bacterial cellulose as bio plastic filler by sonication method

    Science.gov (United States)

    Maryam; Rahmad, D.; Yunizurwan; Kasim, A.; Novelina; Emriadi

    2017-07-01

    Research and development of bioplastic has increased recently as a solution for substitution of conventional plastic which have many negative impacts to environment. However, physical properties and mechanical properties of its still lower than conventional plastic. An alternative solution for that problem is by using fillers that can increase the strength. Bacterial cellulose is considered as potential source for filler, but still need to be explored more. The privileges of bacterial cellulose are easy to get and does not have lignin, pectin, and hemicelluloses which are impurities in other celluloses. This research focused on gaining bacterial cellulose in micro-nano particle form and its impact on increasing the strength of bio plastic. Ultrasonication has been used as method to form micro-nano particle from bacterial cellulose. The result showed this method may form the particle size of bacterial cellulose approximately ± 3μm. Next step, after getting ± 3μm particle of bacterial cellulose, is making bio plastic with casting method by adding 1% of bacterial cellulose, from the total material in making bio plastic. Physical characteristic of the bio plastic which are tensile strength 11.85 MPa, modulus young 3.13 MPa, elongation 4.11% and density 0.42 g/cm3. The numbers of physical properties showwthat, by adding 1% of bacterial cellulose, the strength of bio plastic was significantly increase, even value of tensile strength has complied the international standard for bio plastic.

  10. Nanocellulose prepared by acid hydrolysis of isolated cellulose from sugarcane bagasse

    Science.gov (United States)

    Wulandari, W. T.; Rochliadi, A.; Arcana, I. M.

    2016-02-01

    Cellulose in nanometer range or called by nano-cellulose has attracted much attention from researchers because of its unique properties. Nanocellulose can be obtained by acid hydrolysis of cellulose. The cellulose used in this study was isolated from sugarcane bagasse, and then it was hydrolyzed by 50% sulfuric acid at 40 °C for 10 minutes. Nanocellulose has been characterized by Transmission Electron Microscope (TEM), Particle Size Analyzer (PSA), Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD). Analysis of FTIR showed that there were not a new bond which formed during the hydrolysis process. Based on the TEM analysis, nano-cellulose has a spherical morphology with an average diameter of 111 nm and a maximum distribution of 95.9 nm determined by PSA. The XRD analysis showed that the crystallinity degree of nano-cellulose was higher than cellulose in the amount of 76.01%.

  11. Nanocellulose patents trends: a comprehensive review on patents on cellulose nanocrystals, microfibrillated and bacterial cellulose.

    Science.gov (United States)

    Charreau, Hernan; Foresti, Maria L; Vazquez, Analia

    2013-01-01

    Cellulose nanoparticles (i.e. cellulose elements having at least one dimension in the 1-100 nm range) have received increasing attention during the last decade. This is not only evident in academic articles, but it is also manifested by the increasing number of nanocellulose patents that are published every year. In the current review, nanocellulose patents are reviewed using specific software which provides valuable information on the annual number of patents that have been published throughout the years, main patent owners, most prolific inventors, and patents on the field that have received more citations. Patent statistics on rod-like cellulose nanoparticles extracted from plants by acid hydrolysis (nanocrystals), mechanical treatment leading to microfibrillated cellulose (MFC), and microbially produced nanofibrils (bacterial cellulose, BC) are analyzed in detail. The aim of the current review is to provide researchers with patent information which may help them in visualizing the evolution of nanocellulose technology, both as a whole and also divided among the different nanosized particles that are currently the subject of outstanding scientific attention. Then, patents are not only analyzed by their content, but also by global statistics which will reveal the moment at which different cellulose nanoparticles technologies achieved a breakthrough, the relative interest received by different nanocellulose particles throughout the years, the companies that have been most interested in this technology, the most prolific inventors, and the patents that have had more influence in further developments. It is expected that the results showing the explosion that nanocellulose technology is experiencing in current days will still bring more research on the topic and contribute to the expansion of nanocellulosics applications.

  12. The cellulose resource matrix.

    Science.gov (United States)

    Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

    2013-03-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

  13. Acid hydrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H.

    1980-12-01

    One of the alternatives to increase world production of etha nol is by the hydrolysis of cellulose content of agricultural residues. Studies have been made on the types of hydrolysis: enzimatic and acid. Data obtained from the sulphuric acid hydrolysis of cellulose showed that this process proceed in two steps, with a yield of approximately 95% glucose. Because of increases in cost of alternatives resources, the high demand of the product and the more economic production of ethanol from cellulose materials, it is certain that this technology will be implemented in the future. At the same time further studies on the disposal and reuse of the by-products of this production must be undertaken.

  14. Bacterial Cellulose From Rice Waste Water With Addition Chitosan, Glycerol, And Silver Nanoparticle

    Directory of Open Access Journals (Sweden)

    Eli Rohaeti

    2016-05-01

    Full Text Available This study aimed to prepare silver nanoparticles chemically, deposite silver nanoparticles on bacterial cellulose-chitosan-glycerol composite based rice waste water, as well as test the antibacterial activity of bacterial cellulose and its composite. Preparation of silver nanoparticles was conducted by chemical reduction of silver nitrate solution, as well as trisodium citrate as the reductor. Bacterial cellulose from rice waste water is fermented by the bacteria Acetobacter xylinum for 7 days. The dried bacterial cellulose was composited with chitosan and glycerol by immersion method on 2% of chitosan solution and 0.5% of glycerol solution. UV-Vis spectroscopy is used to determine the formation of silvernanoparticles and Particle Size Analyzer to test the size and particle size distribution. Characterization was conducted to bacterial cellulose and its composite included functional groups by FTIR, the mechanical properties by Tensile Tester, crystallinity by XRD, surface photograph by SEM, and antibacterial test against S. aureus and E. coli by the shake flask turbidimetry method. Silver nanoparticle characterization indicated that silver nanoparticles are formed at a wavelength of 421.80 nm, yellow, diameter particle size of 61.8 nm. SEM images showed that the surface of bacterial cellulose had deposited silver nanoparticles and antibacterial test showed an inhibitory effect of bacterial cellulose, bacterial cellulose-chitosan composite, and bacterial cellulose-chitosan-glycerol composite which are deposited silver nanoparticles against the growth of S. aureus and E. coli bacteria.

  15. A new quality index for benchmarking of different cellulose nanofibrils.

    Science.gov (United States)

    Desmaisons, Johanna; Boutonnet, Elisa; Rueff, Martine; Dufresne, Alain; Bras, Julien

    2017-10-15

    From a single plant source, a wide range of mechanically-deconstructed cellulose nanomaterials can be obtained due to the large number of possible combinations of pre-treatments, mechanical disintegration process, and post-treatments. It leads to the existence of a variety of cellulose nanofibrils with different shapes, morphologies, and properties on the market. The resulting material is actually a complex mixture of nanoscale particles, microfibrillated fibers, and residual fibers on the millimeter scale. Defining a "degree of fibrillation" for determining the final cellulose nanofibril quality is a challenging issue. This study proposes a multi-criteria method to obtain the quality index of cellulose nanofibril suspensions under the form of a unique quantitative grade. According to this method, the influence of different parameters such as pulp conditioning, refining, and hemicellulose content on the defibrillation process is highlighted. This method also allows for the benchmarking of different commercial nanocellulose products. Copyright © 2017. Published by Elsevier Ltd.

  16. The cellulose resource matrix

    NARCIS (Netherlands)

    Keijsers, E.R.P.; Yilmaz, G.; Dam, van J.E.G.

    2013-01-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where

  17. Renewable hybrid nanocatalyst from magnetite and cellulose fortreatment of textile effluents

    Science.gov (United States)

    A hybrid catalyst was prepared using cellulose nanofibrils and magnetite to degrade organic compounds. Cellulose nanofibrils were isolated by mechanical defibrillation producing a suspension used as a matrixfor magnetite particles. The solution of nanofibrils and magnetite was dried and milled resul...

  18. Production and characterization of cellulose nanofibril (CNF) from agricultural waste corn stover

    Science.gov (United States)

    Corn stover, as an agricultural waste, has little economic value. The value-added product cellulose was prepared from corn stover by a relatively simple two-stage process - alkali treatment and bleaching resulting in a >93% purity. The particle size of the corn stover cellulose was reduced by mechan...

  19. Mechanisms behind the stabilizing action of cellulose nanofibrils in wet-stable cellulose foams.

    Science.gov (United States)

    Cervin, Nicholas Tchang; Johansson, Erik; Benjamins, Jan-Willem; Wågberg, Lars

    2015-03-09

    The principal purpose of the investigation was to clarify the mechanisms behind the stabilizing action of cellulose nanofibrils (CNFs) in wet-stable cellulose foams. Following the basic theories for particle-stabilized foams, the investigation was focused on how the surface energy of the stabilizing CNF particles, their aspect ratio and charge density, and the concentration of CNF particles at the air-water interface affect the foam stability and the mechanical properties of a particle-stabilized air-liquid interface. The foam stability was evaluated from how the foam height changed over time, and the mechanical properties of the interface were evaluated as the complex viscoelastic modulus of the interface using the pendant drop method. The most important results and conclusions are that CNFs can be used as stabilizing particles for aqueous foams already at a concentration as low as 5 g/L. The major reasons for this were the small dimensions of the CNF and their high aspect ratio, which is important for gel-formation and the complex viscoelastic modulus of the particle-filled air-water interface. The influence of the aspect ratio was also demonstrated by a much higher foam stability of foams stabilized with CNFs than of foams stabilized by cellulose nanocrystals (CNC) with the same chemical composition. The charge density of the CNFs affects the level of liberation within larger aggregates and hence also the number of contact points at the interface and the gel formation and complex viscoelastic modulus of the air-water interface. The charges also result in a disjoining pressure related to the long-range repulsive electrostatic pressure between particle-stabilized bubbles and hence contribute to foam stability.

  20. Preparation and Characterization of Microcrystalline Cellulose (MCC from Kenaf and Cotton Stem

    Directory of Open Access Journals (Sweden)

    Farshad Mirehki

    2013-11-01

    Full Text Available Cellulose, microcrystalline cellulose (MCC and nanofiber cellulose are the ones of materials which are being used recently as biodegradable filler and reinforcing agent for making composites. In this research, microcrystalline cellulose were prepared from kenaf and cotton bast by hydrochloric acid hydrolysis. The effects of hydrolysis condition on amount of crystallinity and crystal size of MCC were investigated by infrared spectroscopy (FT-IR, X-ray diffraction (XRD and scanning electron microscopy (SEM. Results have shown that in both samples increasing the acid ratio increased the crystallinity; however, the size of crystals did not change. SEM results have shown that after hydrolysis the size of sample particles was micro.

  1. Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

    International Nuclear Information System (INIS)

    Oliveira, Rafael L. de; Barud, Hernane; Ribeiro, Sidney J.L.; Messaddeq, Younes

    2011-01-01

    The chemical modification of cellulose leads to production of derivatives with different properties from those observed for the original cellulose, for example, increased solubility in more traditional solvents. In this work we synthesized four derivatives of cellulose: microcrystalline cellulose, cellulose acetate, methylcellulose and carboxymethylcellulose using bacterial cellulose as a source. These were characterized in terms of chemical and structural changes by examining the degree of substitution (DS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy - NMR 13 C. The molecular weight and degree of polymerization were evaluated by viscometry. The characterization of the morphology of materials and thermal properties were performed with the techniques of X-ray diffraction, electron microscopy images, differential scanning calorimetry (DSC) and thermogravimetric analysis. (author)

  2. Stability mechanism of O/W Pickering emulsions stabilized with regenerated cellulose.

    Science.gov (United States)

    Li, Zhe; Wu, Hairong; Yang, Meng; Xu, Derong; Chen, Jun; Feng, Haishun; Lu, Yao; Zhang, Liming; Yu, Yang; Kang, Wanli

    2018-02-01

    The stability and mechanism of O/W Pickering emulsions stabilized with regenerated cellulose were investigated. The Turbiscan Lab Expert Stabilizer, Particle Size Analyser, and Physica MCR301 Rheometer were used. When the concentration of regenerated cellulose increases, the aggregation of regenerated cellulose, emulsion stability and bulk and interfacial viscoelasticity increase as the diameter of the oil droplets decreases. In addition, the emulsions display a typical gel-like characteristic, and the oil-water interfacial shear rheological behaviour slightly differs from that of the O/W Pickering emulsions. This difference can be attributed to the aggregation of regenerated cellulose in the droplet surface under the shear condition. The emulsions exhibit excellent salt resistance at high salt concentrations. Moreover, the regenerated cellulose displays a better temperature resistance than amphiphilic polymer (AP), which is commonly used in oilfields. Hence, commercially available regenerated cellulose can be used as an ideal candidate for enhanced oil recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Reusable photocatalytic titanium dioxide-cellulose nanofiber films

    Science.gov (United States)

    Alexandra Snyder; Zhenyu Bo; Robert Moon; Jean-Christophe Rochet; Lia. Stanciu

    2013-01-01

    Titanium dioxide (TiO2) is a well-studied photocatalyst that is known to break down organic molecules upon ultraviolet (UV) irradiation. Cellulose nanofibers (CNFs) act as an attractive matrix material for the suspension of photocatalytic particles due to their desirable mechanical and optical properties. In this work, TiO2...

  4. Cellulosic fibril–rubber nanocomposites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2010-06-01

    Full Text Available removes amorphous regions and has been adopted by several researchers. Researchers at CERMAV-CNRS have separated cellulose from various sources like wheat straws and tunicin and have used as reinforcements in polymer matrices [1, 2]. Winter of Cellulose... Research Institute at ESF found that the addition of an ounce (28.35 g) of cellulose nanocrystal to a pound (0.45 kg) of plastic resulted in a 3000-fold increase in strength [3]. This chapter provides an outlook into nanoreinforcements like cellulosic...

  5. Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

    African Journals Online (AJOL)

    The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

  6. Cellulose synthase complex organization and cellulose microfibril structure.

    Science.gov (United States)

    Turner, Simon; Kumar, Manoj

    2018-02-13

    Cellulose consists of linear chains of β-1,4-linked glucose units, which are synthesized by the cellulose synthase complex (CSC). In plants, these chains associate in an ordered manner to form the cellulose microfibrils. Both the CSC and the local environment in which the individual chains coalesce to form the cellulose microfibril determine the structure and the unique physical properties of the microfibril. There are several recent reviews that cover many aspects of cellulose biosynthesis, which include trafficking of the complex to the plasma membrane and the relationship between the movement of the CSC and the underlying cortical microtubules (Bringmann et al. 2012 Trends Plant Sci. 17 , 666-674 (doi:10.1016/j.tplants.2012.06.003); Kumar & Turner 2015 Phytochemistry 112 , 91-99 (doi:10.1016/j.phytochem.2014.07.009); Schneider et al. 2016 Curr. Opin. Plant Biol. 34 , 9-16 (doi:10.1016/j.pbi.2016.07.007)). In this review, we will focus on recent advances in cellulose biosynthesis in plants, with an emphasis on our current understanding of the structure of individual catalytic subunits together with the local membrane environment where cellulose synthesis occurs. We will attempt to relate this information to our current knowledge of the structure of the cellulose microfibril and propose a model in which variations in the structure of the CSC have important implications for the structure of the cellulose microfibril produced.This article is part of a discussion meeting issue 'New horizons for cellulose nanotechnology'. © 2017 The Author(s).

  7. Optimization of some electrochemical etching parameters for cellulose derivatives

    International Nuclear Information System (INIS)

    Chowdhury, Annis; Gammage, R.B.

    1978-01-01

    Electrochemical etching of fast neutron induced recoil particle tracks in cellulose derivatives and other polymers provides an inexpensive and sensitive means of fast neutron personnel dosimetry. A study of the shape, clarity, and size of the tracks in Transilwrap polycarbonate indicated that the optimum normality of the potassium hydroxide etching solution is 9 N. Optimizations have also been attempted for cellulose nitrate, triacetate, and acetobutyrate with respect to such electrochemical etching parameters as frequency, voltage gradient, and concentration of the etching solution. The measurement of differential leakage currents between the undamaged and the neutron damaged foils aided in the selection of optimum frequencies. (author)

  8. Cellulose Synthesis in Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. White; Ann G. Matthysse

    2004-07-31

    We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

  9. Functional biocompatible magnetite-cellulose nanocomposite fibrous networks: Characterization by fourier transformed infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy analysis

    Science.gov (United States)

    Habibi, Neda

    2015-02-01

    The preparation and characterization of functional biocompatible magnetite-cellulose nano-composite fibrous material is described. Magnetite-cellulose nano-composite was prepared by a combination of the solution-based formation of magnetic nano-particles and subsequent coating with amino celluloses. Characterization was accomplished using X-ray powder diffraction (XRD), fourier transformed infrared (FTIR) and field emission scanning electron microscopy (FESEM) analysis. The peaks of Fe3O4 in the XRD pattern of nanocomposite confirm existence of the nanoparticles in the amino cellulose matrix. Magnetite-cellulose particles exhibit an average diameter of roughly 33 nm as demonstrated by field emission scanning electron microscopy. Magnetite nanoparticles were irregular spheres dispersed in the cellulose matrix. The vibration corresponding to the Nsbnd CH3 functional group about 2850 cm-1 is assigned in the FTIR spectra. Functionalized magnetite-cellulose nano-composite polymers have a potential range of application as targeted drug delivery system in biomedical field.

  10. Rheological properties of nanocrystalline cellulose suspensions.

    Science.gov (United States)

    Chen, Yang; Xu, Chunjiang; Huang, Jing; Wu, Defeng; Lv, Qiaolian

    2017-02-10

    Rheological behavior, including linear and nonlinear, as well as transient rheology of nanocrystalline cellulose (NCC) suspensions was studied in this work. Two kinds of polymer solutions, aqueous poly(vinyl alcohol) (PVA) with flexible chain structure and aqueous carboxymethyl cellulose (CMC) with semi-rigid chain structure, were used as the suspension media to further explore the role that the interactions among NCC and polymers played during shear flow. The results reveal that NCC has lower values of percolation threshold in the PVA solution than in the CMC one during small amplitude oscillatory shear (SAOS) flow because the flexible PVA chain has higher adsorbed level onto NCC particles than the negatively charged semi-rigid CMC chain, which is further confirmed by the Fourier transformed infrared (FT-IR) spectroscopy tests. As a result, the NCC suspension shows a weak strain overshoot in PVA solution during large amplitude oscillatory shear (LAOS) flow, which cannot be seen on the one in CMC solution. During startup shear flow, both of these two suspensions show evident stress overshoot behavior with the strain-scaling characteristics, indicating the formation of ordered long-term structure of rod-like NCC particles with self-similarity during flow. However, NCC suspension have far stronger stress overshoot response in CMC solution relative to the one in PVA solution. A possible synergy mechanism between NCC and CMC chain is hence proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

    Science.gov (United States)

    Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

    2012-01-01

    This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

  12. Spray-dried cellulose nanofibers as novel tablet excipient.

    Science.gov (United States)

    Kolakovic, Ruzica; Peltonen, Leena; Laaksonen, Timo; Putkisto, Kaisa; Laukkanen, Antti; Hirvonen, Jouni

    2011-12-01

    The purpose of this study was to evaluate the potential of cellulose nanofibers (also referred as microfibrillated cellulose, nanocellulose, nanofibrillated, or nanofibrillar cellulose) as novel tabletting material. For this purpose, physical and mechanical properties of spray-dried cellulose nanofibers (CNF) were examined, and results were compared to those of two commercial grades of microcrystalline cellulose (MCC), Avicel PH101 and Avicel PH102, which are the most commonly and widely used direct compression excipients. Chemically, MCC and CNF are almost identical, but their physical characteristics, like mechanical properties and surface-to-volume ratio, differ remarkably. The novel material was characterized with respect to bulk and tapped as well as true density, moisture content, and flow properties. Tablets made of CNF powder and its mixtures with MCC with or without paracetamol as model compound were produced by direct compression and after wet granulation. The tensile strength of the tablets made in a series of applied pressures was determined, and yield pressure values were calculated from the measurements. With CNF, both wet granulation and direct compression were successful. During tablet compression, CNF particles were less prone to permanent deformation and had less pronounced ductile characteristics. Disintegration and dissolution studies showed slightly faster drug release from direct compression tablets with CNF, while wet granulated systems did not have any significant difference.

  13. Acetobixan, an inhibitor of cellulose synthesis identified by microbial bioprospecting.

    Directory of Open Access Journals (Sweden)

    Ye Xia

    Full Text Available In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI, named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action to isolate a lead pharmacophore. Analogs of this lead compound were screened for CBI activity, and the most potent analog was named acetobixan. In living Arabidopsis cells visualized by confocal microscopy, acetobixan treatment caused CESA particles localized at the plasma membrane (PM to rapidly re-localize to cytoplasmic vesicles. Acetobixan inhibited 14C-Glc uptake into crystalline cellulose. Moreover, cortical microtubule dynamics were not disrupted by acetobixan, suggesting specific activity towards cellulose synthesis. Previous CBI resistant mutants such as ixr1-2, ixr2-1 or aegeus were not cross resistant to acetobixan indicating that acetobixan targets a different aspect of cellulose biosynthesis.

  14. 21 CFR 573.420 - Ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl cellulose. 573.420 Section 573.420 Food and... Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether containing...

  15. Evaluation of microcrystalline cellulose modifed from alpha ...

    African Journals Online (AJOL)

    Alpha cellulose was obtained from Costus afer and part of it was modified to microcrystalline cellulose (CAMCC). The physicochemical properties of the microcrystalline cellulose were determined and compared with those of commercial microcrystalline cellulose (Avicel 101). The swelling capacity, hydration capacity, loss ...

  16. 21 CFR 172.868 - Ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  17. Preparation of PAN Spinning Solution with Fine Dispersion of Cellulose Microparticles

    Directory of Open Access Journals (Sweden)

    Jee-Woo Yang

    2015-01-01

    Full Text Available This study suggested the optimum conditions for the stable dispersion of cellulose microparticles in PAN spinning dope, which was prepared for spinning the fiber. Many research studies have investigated methods for preparing a variety of carbon fiber precursors in an attempt to control their characteristics according to the applications. In order to prepare PAN fiber that contains fine cellulose particles, it is important to create a uniformly dispersed spinning dope. Minimization of the cellulose particle size was subjected to heat treatment at various temperatures in order to reduce the cohesive force from the hydrogen bonds between the cellulose molecules. Carbonized cellulose microparticles were obtained for efficient dispersion using the physical method and the sedimentation method. Several instrumental analyses were conducted to study the characteristics of the particles and solutions with SEM, FT-IR, XRD, and a particle size analyzer. From the results, the dispersion of the PAN spinning dope with a chemical treatment was superior to the milling method followed by heat treatment. In this study, heat-treating cellulose microparticles at 400°C was found to be the most effective method.

  18. Acetone-based cellulose solvent.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; Heinze, Thomas

    2014-08-01

    Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Cellulose conversion under heterogeneous catalysis.

    Science.gov (United States)

    Dhepe, Paresh L; Fukuoka, Atsushi

    2008-01-01

    In view of current problems such as global warming, high oil prices, food crisis, stricter environmental laws, and other geopolitical scenarios surrounding the use of fossil feedstocks and edible resources, the efficient conversion of cellulose, a non-food biomass, into energy, fuels, and chemicals has received much attention. The application of heterogeneous catalysis could allow researchers to develop environmentally benign processes that lead to selective formation of value-added products from cellulose under relatively mild conditions. This Minireview gives insight into the importance of biomass utilization, the current status of cellulose conversion, and further transformation of the primary products obtained.

  20. Cellulose Depolymerization over Heterogeneous Catalysts.

    Science.gov (United States)

    Shrotri, Abhijit; Kobayashi, Hirokazu; Fukuoka, Atsushi

    2018-02-14

    Cellulosic biomass is the largest source of renewable organic carbon on our planet. Cellulose accounts for 40-50 wt % of this lignocellulose, and it is a feedstock for industrially important chemicals and fuels. The first step in cellulose conversion involves its depolymerization to glucose or to its hydrogenated product sorbitol. The hydrolysis of cellulose to glucose by homogeneous mineral acids was the subject of research for almost a century. However, homogeneous acids have significant drawbacks and are neither economical nor environmentally friendly. In 2006, our group reported for the first time the ability of heterogeneous catalysts to depolymerize cellulose through hydrolytic hydrogenation to produce sorbitol. Later, we reported the hydrolysis of cellulose to glucose using carbon catalyst containing weakly acidic functional groups. Understanding the reaction between cellulose and heterogeneous catalyst is a challenge as the reaction occurs between a solid substrate and a solid catalyst. In this Account, we describe our efforts for the conversion of cellulose to sorbitol and glucose using heterogeneous catalysts. Sorbitol is produced by sequential hydrolysis and hydrogenation of cellulose in one pot. We reported sorbitol synthesis from cellulose in the presence of supported metal catalysts and H 2 gas. The reducing environment of the reaction prevents byproduct formation, and harsh reaction conditions can be used to achieve sorbitol yield of up to 90%. Glucose is produced by acid catalyzed hydrolysis of cellulose, a more challenging reaction owing to the tendency of glucose to rapidly decompose in hot water. Sulfonated carbons were first reported as active catalysts for cellulose hydrolysis, but they were hydrothermally unstable under the reaction conditions. We found that carbon catalysts bearing weakly acidic functional groups such as hydroxyl and carboxylic acids are also active. Weakly acidic functional groups are hydrothermally stable, and a soluble

  1. Cellulose microfibril structure: inspirations from plant diversity

    Science.gov (United States)

    Roberts, A. W.

    2018-03-01

    Cellulose microfibrils are synthesized at the plasma membrane by cellulose synthase catalytic subunits that associate to form cellulose synthesis complexes. Variation in the organization of these complexes underlies the variation in cellulose microfibril structure among diverse organisms. However, little is known about how the catalytic subunits interact to form complexes with different morphologies. We are using an evolutionary approach to investigate the roles of different catalytic subunit isoforms in organisms that have rosette-type cellulose synthesis complexes.

  2. Preparation and characterization of aminobenzyl cellulose by two step synthesis from native cellulose

    Science.gov (United States)

    Synthesis and structural characterizations of nitro- and amino-benzyl cellulose were carried out. Cellulose derivatives were synthesized by etherification. Nitrobenzylation produced 80% yield by treating a mixture of microcrystalline cellulose, 4-dimethyl aminopyridine and 4-nitrobenzyl chloride at ...

  3. Eggshell and Bacterial Cellulose Composite Membrane as Absorbent Material in Active Packaging

    Directory of Open Access Journals (Sweden)

    S. Ummartyotin

    2016-01-01

    Full Text Available Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with bacterial cellulose suspension and it was casted as a composite film. CaCO3 derived from eggshell was compared with its commercial availability. It can be noted that good dispersion of eggshell particle was prepared. Eggshell particle was irregular in shape with a variation in size. It existed in bacterial cellulose network. Characterization on composite was focused on thermal and mechanical properties. It showed that flexibility and thermal stability of composite were enhanced. No significant effect of mechanical properties was therefore observed. The thermal stability of composite was stable up to 300°C. The adsorption experiment on water and vegetable oil capacity was performed. The enhancement on adsorption was due to the existence of eggshell in bacterial cellulose composite. It exhibited the potential to be a good candidate for absorbent material in active packaging.

  4. Practical screening of purified cellobiohydrolases and endoglucanases with α-cellulose and specification of hydrodynamics

    Directory of Open Access Journals (Sweden)

    Jäger Gernot

    2010-08-01

    Full Text Available Abstract Background It is important to generate biofuels and society must be weaned from its dependency on fossil fuels. In order to produce biofuels, lignocellulose is pretreated and the resulting cellulose is hydrolyzed by cellulases such as cellobiohydrolases (CBH and endoglucanases (EG. Until now, the biofuel industry has usually applied impractical celluloses to screen for cellulases capable of degrading naturally occurring, insoluble cellulose. This study investigates how these cellulases adsorb and hydrolyze insoluble α-cellulose − considered to be a more practical substrate which mimics the alkaline-pretreated biomass used in biorefineries. Moreover, this study investigates how hydrodynamics affects cellulase adsorption and activity onto α-cellulose. Results First, the cellulases CBH I, CBH II, EG I and EG II were purified from Trichoderma reesei and CBH I and EG I were utilized in order to study and model the adsorption isotherms (Langmuir and kinetics (pseudo-first-order. Second, the adsorption kinetics and cellulase activities were studied under different hydrodynamic conditions, including liquid mixing and particle suspension. Third, in order to compare α-cellulose with three typically used celluloses, the exact cellulase activities towards all four substrates were measured. It was found that, using α-cellulose, the adsorption models fitted to the experimental data and yielded parameters comparable to those for filter paper. Moreover, it was determined that higher shaking frequencies clearly improved the adsorption of cellulases onto α-cellulose and thus bolstered their activity. Complete suspension of α-cellulose particles was the optimal operating condition in order to ensure efficient cellulase adsorption and activity. Finally, all four purified cellulases displayed comparable activities only on insoluble α-cellulose. Conclusions α-Cellulose is an excellent substrate to screen for CBHs and EGs. This current investigation

  5. INFLUENCE OF CELLULOSE POLYMERIZATION DEGREE AND CRYSTALLINITY ON KINETICS OF CELLULOSE DEGRADATION

    OpenAIRE

    Edita Jasiukaitytė-Grojzdek,; Matjaž Kunaver,; Ida Poljanšek

    2012-01-01

    Cellulose was treated in ethylene glycol with p-toluene sulfonic acid monohydrate as a catalyst at different temperatures. At the highest treatment temperature (150 °C) liquefaction of wood pulp cellulose was achieved and was dependant on cellulose polymerization degree (DP). Furthermore, the rate of amorphous cellulose weight loss was found to increase with cellulose degree of polymerization, while the rate of crystalline cellulose weight loss was reciprocal to the size of the crystallites. ...

  6. Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

    Directory of Open Access Journals (Sweden)

    Hernane S. Barud

    2011-01-01

    Full Text Available Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by “in situ” preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and absorption in the UV-Visible (350 nm to 600 nm. Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

  7. Opportunity for profitable investments in cellulosic biofuels

    International Nuclear Information System (INIS)

    Babcock, Bruce A.; Marette, Stephan; Treguer, David

    2011-01-01

    Research efforts to allow large-scale conversion of cellulose into biofuels are being undertaken in the US and EU. These efforts are designed to increase logistic and conversion efficiencies, enhancing the economic competitiveness of cellulosic biofuels. However, not enough attention has been paid to the future market conditions for cellulosic biofuels, which will determine whether the necessary private investment will be available to allow a cellulosic biofuels industry to emerge. We examine the future market for cellulosic biofuels, differentiating between cellulosic ethanol and 'drop-in' cellulosic biofuels that can be transported with petroleum fuels and have equivalent energy values. We show that emergence of a cellulosic ethanol industry is unlikely without costly government subsidies, in part because of strong competition from conventional ethanol and limits on ethanol blending. If production costs of drop-in cellulosic biofuels fall enough to become competitive, then their expansion will not necessarily cause feedstock prices to rise. As long as local supplies of feedstocks that have no or low-valued alternative uses exist, then expansion will not cause prices to rise significantly. If cellulosic feedstocks come from dedicated biomass crops, then the supply curves will have a steeper slope because of competition for land. - Research highlights: → The likelihood of a significant cellulosic ethanol industry in the US looks dim. → Drop-in biofuels made from cellulosic feedstocks have a more promising future. → The spatial dimension of markets for cellulosic feedstocks will be limited. → Corn ethanol will be a tough competitor for cellulosic ethanol.

  8. Morphology of Cellulose and Cellulose Blend Thin FilmsMorphology of cellulose and cellulose blend thin films

    Science.gov (United States)

    Lu, Rui

    Cellulose is the most abundant, renewable, biocompatible and biodegradable natural polymer. Cellulose exhibits excellent chemical and mechanical stability, which makes it useful for applications such as construction, filtration, bio-scaffolding and packaging. It is useful to study amorphous cellulose as most reactions happen in the non-crystalline regions first and at the edge of crystalline regions. In this study, amorphous thin films of cotton linter cellulose with various thicknesses were spincoated on silicon wafers from cellulose solutions in dimethyl sulfoxide / ionic liquid mixtures. Optical microscopy and atomic force microscopy indicated that the morphology of as-cast films was sensitive to the film preparation conditions. A sample preparation protocol with low humidity system was developed to achieve featureless smooth films over multiple length scales from nanometers to tens of microns. X-ray reflectivity, X-ray diffraction, Fourier transform infrared spectroscopy and high resolution sum-frequency generation vibrational spectroscopy were utilized to confirm that there were no crystalline regions in the films. One- and three- layer models were used to analyze the X-ray reflectivity data to obtain information about roughness, density and interfacial roughness as a function of film thickness from 10-100nm. Stability tests of the thin films were conducted under harsh conditions including hot water, acid and alkali solutions. The stability of thin films of cellulose blended with the synthetic polymer, polyacrylonitrile, was also investigated. The blend thin films improved the etching resistance to alkali solutions and retained the stability in hot water and acid solutions compared to the pure cellulose films.

  9. Ionic liquid processing of cellulose.

    Science.gov (United States)

    Wang, Hui; Gurau, Gabriela; Rogers, Robin D

    2012-02-21

    Utilization of natural polymers has attracted increasing attention because of the consumption and over-exploitation of non-renewable resources, such as coal and oil. The development of green processing of cellulose, the most abundant biorenewable material on Earth, is urgent from the viewpoints of both sustainability and environmental protection. The discovery of the dissolution of cellulose in ionic liquids (ILs, salts which melt below 100 °C) provides new opportunities for the processing of this biopolymer, however, many fundamental and practical questions need to be answered in order to determine if this will ultimately be a green or sustainable strategy. In this critical review, the open fundamental questions regarding the interactions of cellulose with both the IL cations and anions in the dissolution process are discussed. Investigations have shown that the interactions between the anion and cellulose play an important role in the solvation of cellulose, however, opinions on the role of the cation are conflicting. Some researchers have concluded that the cations are hydrogen bonding to this biopolymer, while others suggest they are not. Our review of the available data has led us to urge the use of more chemical units of solubility, such as 'g cellulose per mole of IL' or 'mol IL per mol hydroxyl in cellulose' to provide more consistency in data reporting and more insight into the dissolution mechanism. This review will also assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate 'greenness' of any process (142 references).

  10. Microfibrillated cellulose: morphology and accessibility

    Energy Technology Data Exchange (ETDEWEB)

    Herrick, F.W.; Casebier, R.L.; Hamilton, J.K.; Sandberg, K.R.

    1983-01-01

    Microfibrillated cellulose (MFC) is prepared by subjecting dilute slurries of cellulose fibers to repeated high-pressure homogenizing action. A highly microfibrillated product will have a gel-like appearance at 2% concentration in water. Such gels have pseudoplastic viscosity properties and are very fluid when stirred at high shear rate. The relative viscosity of 2% MFC dispersions may be used as a measure of the degree of homogenization or microfibrillation of a given wood cellulose pulp. The water retention value of an MFC product can also be used as an indicator for degree of homogenization. Structurally, MFC appears to be a web of interconnected fibrils and microfibrils, the latter having diameters in the range 10-100 nm as observed in scanning and transmission electron micrographs. Chemical studies have revealed that MFC is only moderately degraded, while being greatly expanded in surface area. The accessibility of cellulose in MFC is only moderately degraded, while being greatly expanded in surface area. The accessibility of cellulose in MFC toward chemical reagents is greatly increased. Higher reactivity was demonstrated in dilute cupriethylenediamine solubility, triphenylmethylation, acetylation, periodate oxidation, and mineral acid and cellulase enzyme hydrolysis rates. 16 references, 8 figures, 7 tables.

  11. Raman spectroscopy in the analysis of cellulose nanomaterials

    Science.gov (United States)

    Umesh P. Agarwal

    2017-01-01

    Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when...

  12. 2013 Cellulosic Biofuel Standard: Direct Final Rule

    Science.gov (United States)

    The direct final action is to revise the 2013 cellulosic biofuel standard. This action follows from EPA having granted API's and AFPM's petitions for reconsideration of the 2013 cellulosic biofuel standard published on August 15, 2013.

  13. Characterization of Cellulose Synthesis in Plant Cells

    Science.gov (United States)

    Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-shu

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

  14. A Molecular Description of Cellulose Biosynthesis

    Science.gov (United States)

    McNamara, Joshua T.; Morgan, Jacob L.W.; Zimmer, Jochen

    2016-01-01

    Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed. PMID:26034894

  15. Characterization of Cellulose Synthesis in Plant Cells

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Maleki

    2016-01-01

    Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

  16. Cellulose nanocrystal properties and their applications

    Directory of Open Access Journals (Sweden)

    mahdi jonoobi

    2015-05-01

    Full Text Available The main purpose of this work is to provide an overview of recent research in the area of cellulose nonmaterials production from different sources. Due to their abundance, their renewability, high strength and stiffness, being eco-friendly, and low weight; numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high performance applications. This work covers an introduction into the nano cellulose definition as well as used methods for isolation of nanomaterials (nanocrystals from various sources. The rod-like cellulose nanocrystals (CNC can be isolated from sources like wood, plant fibers, agriculture and industrial bio residues, tunicates, and bacterial cellulose using acid hydrolysis process. Following this, the paper focused on characterization methods, materials properties and structure. The current review is a comprehensive literature regarding the nano cellulose isolation and demonstrates the potential of cellulose nanomaterials to be used in a wide range of high-tech applications.

  17. Spray-dried nanofibrillar cellulose microparticles for sustained drug release.

    Science.gov (United States)

    Kolakovic, Ruzica; Laaksonen, Timo; Peltonen, Leena; Laukkanen, Antti; Hirvonen, Jouni

    2012-07-01

    Nanofibrillar cellulose (also referred to as cellulose nanofibers, nanocellulose, microfibrillated or nanofibrillated cellulose) has gained a lot of attention in recent years in different research areas including biomedical applications. In this study we have evaluated the applicability of nanofibrillar cellulose (NFC) as a material for the formation of matrix systems for sustained drug delivery. For that purpose, drug loaded NFC microparticles were produced by a spray drying method. The microparticles were characterized in terms of size and morphology, total drug loading, and physical state of the encapsulated drug. Drug release from the microparticles was assessed by dissolution tests, and suitable mathematical models were used to explain the drug releasing kinetics. The particles had spherical shapes with diameters of around 5 μm; the encapsulated drug was mainly in amorphous form. The controlled drug release was achieved. The drug releasing curves were fitted to a mathematical model describing the drug releasing kinetics from a spherical matrix. Different drugs had different release kinetics, which was a consequence of several factors, including different solubilities of the drugs in the chosen medium and different affinities of the drugs to the NFC. It can be concluded that NFC microparticles can sustain drug release by forming a tight fiber network and thus limit drug diffusion from the system. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Characterization of Epoxy Composites Reinforced with Wax Encapsulated Microcrystalline Cellulose

    Directory of Open Access Journals (Sweden)

    Yuanfeng Pan

    2016-11-01

    Full Text Available The effect of paraffin wax encapsulated microcrystalline cellulose (EMC particles on the mechanical and physical properties of EMC/epoxy composites were investigated. It was demonstrated that the compatibility between cellulose and epoxy resin could be maintained due to partial encapsulation resulting in an improvement in epoxy composite mechanical properties. This work was unique because it was possible to improve the physical and mechanical properties of the EMC/epoxy composites while encapsulating the microcrystalline cellulose (MCC for a more homogeneous dispersion. The addition of EMC could increase the stiffness of epoxy composites, especially when the composites were wet. The 1% EMC loading with a 1:2 ratio of wax:MCC demonstrated the best reinforcement for both dry and wet properties. The decomposition temperature of epoxy was preserved up to a 5% EMC loading and for different wax:MCC ratios. An increase in wax encapsulated cellulose loading did increase water absorption but overall this absorption was still low (<1% for all composites.

  19. Development of nonflammable cellulosic foams

    Science.gov (United States)

    Luttinger, M.

    1972-01-01

    The development of a moldable cellulosic foam for use in Skylab instrument storage cushions is considered. Requirements include density of 10 lb cu ft or less, minimal friability with normal handling, and nonflammability in an atmosphere of 70 percent oxygen and 30 percent nitrogen at 6.2 psia. A study of halogenated foam components was made, including more highly chlorinated binders, halogen-containing additives, and halogenation of the cellulose. The immediate objective was to reduce the density of the foam through reduction in inorganic phosphate without sacrificing flame-retarding properties of the foams. The use of frothing techniques was investigated, with particular emphasis on a urea-formaldehyde foam. Halogen-containing flame retardants were deemphasized in favor of inorganic salts and the preparation of phosphate and sulphate esters of cellulose. Utilization of foam products for civilian applications was also considered.

  20. Radiation modification of cellulose pulps. Preparation of cellulose derivatives

    International Nuclear Information System (INIS)

    Iller, E.; Zimek, Z.; Stupinska, H.; Mikolajczyk, W; Starostka, P.

    2005-01-01

    One of the most common methods of cellulose pulp modification (activation) applied in the production process of cellulose derivatives is the treatment of the pulp with NaOH solutions leading to the formation of alkalicellulose. The product then undergoes a prolonged process of maturation by its storage under specific conditions. The goal of the process is lowering of the molecular weight of cellulose down to the level resulting from various technological requirements. The process is time-consuming and costly; besides, it requires usage of large-capacity technological vessels and produces considerable amounts of liquid waste. Therefore, many attempts have been made to limit or altogether eliminate the highly disadvantageous stage of cellulose treatment with lye. One of the alternatives proposed so far is the radiation treatment of the cellulose pulp. In the pulp exposed to an electron beam, the bonds between molecules of D-antihydroglucopiranoses loosen and the local crystalline lattice becomes destroyed. This facilitates the access of chemical reagents to the inner structure of the cellulose and, in consequence, eliminates the need for the prolonged maturation of alkalicellulose, thus reducing the consumption of chemicals by the whole process. Research aimed at the application of radiation treatment of cellulose pulp for the production of cellulose derivatives has been conducted by a number of scientific institutions including the Institute of Nuclear Chemistry and Technology, Institute of Biopolymers and Chemical Fibres, and Pulp and Paper Research Institute. For the investigations and assessment of the molecular, hypermolecular, morphologic properties and the chemical reactivity, cellulose pulps used for chemical processing, namely Alicell, Borregaard and Ketchikan, as well as paper pulps made from pine and birch wood were selected. The selected cellulose pulps were exposed to an electron beam with an energy of 10 MeV generated in a linear electron accelerator

  1. Facile Fabrication of 100% Bio-based and Degradable Ternary Cellulose/PHBV/PLA Composites

    Directory of Open Access Journals (Sweden)

    Tao Qiang

    2018-02-01

    Full Text Available Modifying bio-based degradable polymers such as polylactide (PLA and poly(hydroxybutyrate-co-hydroxyvalerate (PHBV with non-degradable agents will compromise the 100% degradability of their resultant composites. This work developed a facile and solvent-free route in order to fabricate 100% bio-based and degradable ternary cellulose/PHBV/PLA composite materials. The effects of ball milling on the physicochemical properties of pulp cellulose fibers, and the ball-milled cellulose particles on the morphology and mechanical properties of PHBV/PLA blends, were investigated experimentally and statistically. The results showed that more ball-milling time resulted in a smaller particle size and lower crystallinity by way of mechanical disintegration. Filling PHBV/PLA blends with the ball-milled celluloses dramatically increased the stiffness at all of the levels of particle size and filling content, and improved their elongation at the break and fracture work at certain levels of particle size and filling content. It was also found that the high filling content of the ball-milled cellulose particles was detrimental to the mechanical properties for the resultant composite materials. The ternary cellulose/PHBV/PLA composite materials have some potential applications, such as in packaging materials and automobile inner decoration parts. Furthermore, filling content contributes more to the variations of their mechanical properties than particle size does. Statistical analysis combined with experimental tests provide a new pathway to quantitatively evaluate the effects of multiple variables on a specific property, and figure out the dominant one for the resultant composite materials.

  2. Properties of microcrystalline cellulose obtained from coconut ...

    African Journals Online (AJOL)

    The study revealed that the cellulose material compares favourably with Avicel PH 101 as well as official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose. Keywords: Coconut fruit fibre, microcrystalline cellulose, powder properties. Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: ...

  3. Adsorption and desorption of cellulose derivatives

    NARCIS (Netherlands)

    Hoogendam, C.W.

    1998-01-01

    Cellulose derivatives, in particular carboxymethyl cellulose (CMC) are used in many (industrial) applications. The aim of this work is to obtain insight into the adsorption mechanism of cellulose derivatives on solid-liquid interfaces.

    In chapter

  4. Physicochemical analysis of cellulose from microalgae ...

    African Journals Online (AJOL)

    ... cellulose of microalgae for the vegetal cellulose, as seen in the simple technical extraction, the yield and the procurement of uncontaminated molecule with lignin. This substitution will contribute in protecting the environment. Keywords: Cellulose, Nannochloropsis gaditana, procedure extraction, structural characterization ...

  5. 21 CFR 172.870 - Hydroxypropyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydroxypropyl cellulose. 172.870 Section 172.870... CONSUMPTION Multipurpose Additives § 172.870 Hydroxypropyl cellulose. The food additive hydroxypropyl cellulose may be safely used in food, except standardized foods that do not provide for such use, in...

  6. Method of producing thin cellulose nitrate film

    International Nuclear Information System (INIS)

    Lupica, S.B.

    1975-01-01

    An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent

  7. Bioengineering cellulose-hemicellulose networks in plants

    NARCIS (Netherlands)

    Obembe, O.

    2006-01-01

    The interactions between cellulose and hemicellulose in the cell walls are important in the industrial application of the cellulose (natural) fibres. We strive to modify these interactions (i) by interfering with cellulose biosynthesis and (ii) by direct interference of the

  8. Regioselective Synthesis of Cellulose Ester Homopolymers

    Science.gov (United States)

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  9. Iodine catalyzed acetylation of starch and cellulose

    Science.gov (United States)

    Starch and cellulose, earth's most abundant biopolymers, are of tremendous economic importance. Over 90% of cotton and 50% of wood are made of cellulose. Wood and cotton are the major resources for all cellulose products such as paper, textiles, construction materials, cardboard, as well as such c...

  10. Studies on Nano Barium Strontium Titanate/Cellulose Derivatives Composites

    Directory of Open Access Journals (Sweden)

    Y. Hamzeh

    2009-12-01

    Full Text Available Studies were carried out on the preparation and properties of the composites made from cellulose acetate butyrate and cellulose acetate propionate with various amounts of barium strontium titanate nano-particle. The nano-particles of barium strontium titanate (BST with formulation of Ba0.77Sr0.23TiO3 were made by sol-gel method and their purity and particle size were analyzed by X-ray diffraction (XRD. The composites were prepared with BST nano-particle loading of 10 to 50 vol%, and their distribution in the composites studied using SEM imaging. The dielectric constant of the composites was measured at 1 kHz and 100 kHz at room temperature. It was found that the adopted procedure produced dense and uniform composites. The dielectric constant of the composites increased with the solid contentof BST and followed the modified Lichtenecker equation. The increasing rate of dielectric constant with increased BST content was more pronounced for the BST/CAP composite. The dielectric constant of the composites decreased withincreasing the frequency which was more obvious at higher loading of BST nano-particle

  11. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  12. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Science.gov (United States)

    Isik, Mehmet; Sardon, Haritz; Mecerreyes, David

    2014-01-01

    Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels. PMID:25000264

  13. Fracture Surface Morphology and Impact Strength of Cellulose/PLA Composites.

    Science.gov (United States)

    Gao, Honghong; Qiang, Tao

    2017-06-07

    Polylactide (PLA)-based composite materials reinforced with ball-milled celluloses were manufactured by extrusion blending followed by injection molding. Their surface morphology from impact fracture were imaged with scanning electron microscopy (SEM) and investigated by calculating their fractal dimensions. Then, linear regression was used to explore the relationship between fractal dimension and impact strength of the resultant cellulose/PLA composite materials. The results show that filling the ball-milled celluloses into PLA can improve the impact toughness of PLA by a minimum of 38%. It was demonstrated that the fracture pattern of the cellulose/PLA composite materials is different from that of pristine PLA. For the resultant composite materials, the fractal dimension of the impact fractured surfaces increased with increasing filling content and decreasing particle size of the ball-milled cellulose particles. There were highly positive correlations between fractal dimension of the fractured surfaces and impact strength of the cellulose/PLA composites. However, the linearity between fractal dimension and impact strength were different for the different methods, due to their different R-squared values. The approach presented in this work will help to understand the structure-property relationships of composite materials from a new perspective.

  14. Preparation and Characterization of Cellulose and Nanocellulose from Agro-industrial Waste - Cassava Peel

    Science.gov (United States)

    Widiarto, S.; Yuwono, S. D.; Rochliadi, A.; Arcana, I. M.

    2017-02-01

    Cassava peel is an agro-industrial waste which is available in huge quantities in Lampung Province of Indonesia. This work was conducted to evaluate the potential of cassava peel as a source of cellulose and nanocellulose. Cellulose was extracted from cassava peel by using different chemical treatment, and the nanocellulose was prepared by hydrolysis with the use of sulfuric acid. The best methods of cellulose extraction from cassava peels are using alkali treatment followed by a bleaching process. The cellulose yield from this methods was 17.8% of dry base cassava peel, while the yield from nitric and sulfuric methods were about 10.78% and 10.32% of dry base cassava peel respectively. The hydrolysis was performed at the temperature of 50 °C for 2 hours. The intermediate reaction product obtained after each stage of the treatments was characterized. Fourier transform infrared spectroscopy showed the removal of non-cellulosic constituent. X-ray Diffraction (XRD) analysis revealed that the crystallinity of cellulose increased after hydrolysis. Morphological investigation was performed using Scanning Electron Microscopy (SEM). The size of particle was confirmed by Particle Size Analyzer (PSA) and Transmission Electron Microscopy (TEM).

  15. Physical and mechanical properties of microcrystalline cellulose prepared from local agricultural residues

    International Nuclear Information System (INIS)

    El-Sakhawy, M.M.; Hassan, M.L.

    2005-01-01

    Microcrystalline cellulose (MCC) was prepared from local agricultural residues, namely, bagasse, rice straw, and cotton stalks bleached pulps. Hydrolysis of bleached pulps was carried out using hydrochloric or sulfuric acid to study the effect of the acid used on the properties of produced microcrystalline cellulose such as degree of polymerization (DP), crystallinity index (CrI), crystallite size, bulk density, particle size, and thermal stability. The mechanical properties of tablets made from microcrystalline cellulose of the different agricultural residues were tested and compared to commercial grade MCC. The use of rice straw pulp in different proportions as a source of silica to prepare silicified microcrystalline cellulose (SMCC) was carried out. The effect of the percent of silica on the mechanical properties of tablets before and after wet granulation was tested

  16. Advancing cellulose-based nanotechnology

    Science.gov (United States)

    Theodore H. Wegner; Philip E. Jones

    2006-01-01

    Nanotechnology has applications across most economic sectors and allows the development of new enabling science with broad commercial potential. Cellulose and lignocellulose have great potential as nanomaterials because they are abundant, renewable, have a nanofibrillar structure, can be made multifunctional, and self-assemble into well-defined architectures. To...

  17. Ignition inhibitors for cellulosic materials

    International Nuclear Information System (INIS)

    Alvares, N.J.

    1976-01-01

    By exposing samples to various irradiance levels from a calibrated thermal radiation source, the ignition responses of blackened alpha-cellulose and cotton cloth with and without fire-retardant additives were compared. Samples treated with retardant compounds which showed the most promise were then isothermally pyrolyzed in air for comparisons between the pyrolysis rates. Alpha-cellulose samples containing a mixture of boric acid, borax, and ammonium di-hydrogen phosphate could not be ignited by irradiances up to 4.0 cal cm -2 s-1 (16.7 W/cm 2 ). At higher irradiances the specimens ignited, but flaming lasted only until the flammable gases were depleted. Cotton cloth containing a polymeric retardant with the designation THPC + MM was found to be ignition-resistant to all irradiances below 7.0 cal cm -2 s -1 (29.3 W/cm 2 ). Comparison of the pyrolysis rates of the retardant-treated alpha-cellulose and the retardant-treated cotton showed that the retardant mechanism is qualitatively the same. Similar ignition-response measurements were also made with specimens exposed to ionizing radiation. It was observed that gamma radiation results in ignition retardance of cellulose, while irradiation by neutrons does not

  18. Polyvinyl alcohol–cellulose composite

    Indian Academy of Sciences (India)

    We have made an attempt to prepare taste sensor material by using functionalized polymer without any lipid. PVA–cellulose composite has been modified to use as the sensor material. The research work covers polymer membrane preparation, morphology study and structural characterization of the membrane and study of ...

  19. WOOD CELLULOSE ACETATE MEMBRANE 179

    African Journals Online (AJOL)

    DR. AMINU

    2013-06-01

    Jun 1, 2013 ... Science. 297: 803-806. Guthrie, J.T and Tune, P.D. (1991). The preparation, characterization and application of cellulose-. MMA graft copolymers. J. Polym. Sci. 29, 1301-. 1309. Hamiltion, J..K. and Mitachell, R.L. (1965). Encyclopaedia of polymer science and technology, vol. 3. (Biakales, N..M. edn). .John.

  20. Controlled grafting of cellulose diacetate

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Janata, Miroslav; Látalová, Petra; Kříž, Jaroslav; Čadová, Eva; Toman, Luděk

    2006-01-01

    Roč. 47, č. 8 (2006), s. 2587-2595 ISSN 0032-3861 Institutional research plan: CEZ:AV0Z40500505 Keywords : cellulose diacetate * functionalization * ATRP Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.773, year: 2006

  1. Magnetically responsive bacterial cellulose: Synthesis and magnetic studies

    Science.gov (United States)

    Vitta, Satish; Drillon, Marc; Derory, A.

    2010-09-01

    Bacterial cellulose with its porous network structure was used as a support to precipitate Ni nanoparticles by room temperature chemical reduction of Ni-chloride hexahydrate. The room temperature reduction in an aqueous environment results in the formation of crystalline Ni nanoparticles of size 10 to 60 nm inside the bacterial cellulose along with Ni(OH)2. The nanocrystals have an equiaxed shape and are found both as individual particles as well as small aggregates depending on the porous network structure of cellulose matrix. The bacterial cellulose does not undergo any change and retains its crystal structure even after chemical reduction reaction. The Ni loaded bacterial cellulose is found to be ferromagnetic at room temperature with a saturation magnetization of 2.81 emu g-1 which increases by an order of magnitude to 21.8 emu g-1 at 1.8 K. The coercive field also increases by two orders of magnitude from 28 G at 300 K to 2900 G at 1.8 K. The zero field cooled magnetization however exhibits a superparamagnetic behavior with a peak at 20 K, the blocking temperature and this behavior is observed even in ac magnetization. The magnetization decrease with increasing temperature up to 400 K, when extrapolated to high temperatures using a power law indicates a Curie transition at 500 K, much lower than the Curie temperature of bulk Ni. The fraction of isolated superparamagnetic nanoparticles present in the composite was estimated from the saturation magnetization and is found to be ˜88%. These results clearly highlight the presence of two separate magnetic phases, superparamagnetic, and ferromagnetic, and the role of various magnetic interactions in the collective magnetic behavior of Ni nanoparticles in the composite structure.

  2. Cellulose nanomaterials in water treatment technologies.

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

    2015-05-05

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

  3. Polymorphy in native cellulose: recent developments

    International Nuclear Information System (INIS)

    Atalla, R.H.

    1984-01-01

    In a number of earlier studies, the authors developed a model of cellulose structure based on the existence of two stable, linearly ordered conformations of the cellulose chain that are dominant in celluloses I and II, respectively. The model rests on extensive Raman spectral observations together with conformational considerations and solid-state 13 C-NMR studies. More recently, they have proposed, on the basis of high resolution solid-state 13 C-NMR observations, that native celluloses are composites of two distinct crystalline forms that coexist in different proportions in all native celluloses. In the present work, they examine the Raman spectra of the native celluloses, and reconcile their view of conformational differences with the new level of crystalline polymorphy of native celluloses revealed in the solid-state 13 C-NMR investigations

  4. Cellulose Nanomaterials in Water Treatment Technologies

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles François; Wiesner, Mark R.

    2015-01-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials’ potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials’ beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

  5. Copper removal using electrosterically stabilized nanocrystalline cellulose.

    Science.gov (United States)

    Sheikhi, Amir; Safari, Salman; Yang, Han; van de Ven, Theo G M

    2015-06-03

    Removal of heavy metal ions such as copper using an efficient and low-cost method with low ecological footprint is a critical process in wastewater treatment, which can be achieved in a liquid phase using nanoadsorbents such as inorganic nanoparticles. Recently, attention has turned toward developing sustainable and environmentally friendly nanoadsorbents to remove heavy metal ions from aqueous media. Electrosterically stabilized nanocrystalline cellulose (ENCC), which can be prepared from wood fibers through periodate/chlorite oxidation, has been shown to have a high charge content and colloidal stability. Here, we show that ENCC scavenges copper ions by different mechanisms depending on the ion concentration. When the Cu(II) concentration is low (C0≲200 ppm), agglomerates of starlike ENCC particles appear, which are broken into individual starlike entities by shear and Brownian motion, as evidenced by photometric dispersion analysis, dynamic light scattering, and transmission electron microscopy. On the other hand, at higher copper concentrations, the aggregate morphology changes from starlike to raftlike, which is probably due to the collapse of protruding dicarboxylic cellulose (DCC) chains and ENCC charge neutralization by copper adsorption. Such raftlike structures result from head-to-head and lateral aggregation of neutralized ENCCs as confirmed by transmission electron microscopy. As opposed to starlike aggregates, the raftlike structures grow gradually and are prone to sedimentation at copper concentrations C0≳500 ppm, which eliminates a costly separation step in wastewater treatment processes. Moreover, a copper removal capacity of ∼185 mg g(-1) was achieved thanks to the highly charged DCC polyanions protruding from ENCC. These properties along with the biorenewability make ENCC a promising candidate for wastewater treatment, in which fast, facile, and low-cost removal of heavy metal ions is desired most.

  6. Surface modification of cellulose isolated from Sesamun indicum underutilized seed: A means of enhancing cellulose hydrophobicity

    Directory of Open Access Journals (Sweden)

    Adewale Adewuyi

    2017-09-01

    Full Text Available Cellulose (SC isolated from sesame seed (SS was surface modified with the introduction of an ester functional group via a simple reaction to produce the modified product (SA. SS, SC and SA were characterized using Fourier transform infrared (FTIR, X-ray diffraction (XRD, thermogravimetric analysis (TG, particle size distribution (PSD, zeta potential and scanning electron microscopy (SEM. SC and SA were evaluated for their water holding capacity (WC, oil holding capacity (OC, swelling capacity (SW and their ability to adsorb heavy metals. The FTIR revealed peaks corresponding to the formation of the ester functional group at the surface of SA. The crystallinity of SC was 28.02% but after the modification, it increased to 77.03% in SA. The PSD of SC and SA was both monomodal with sizes of 10.1305 μm in SC and 10.2511 μm in SA. The adsorption capacity of SC towards Pb (II and Cu (II ions was higher than that of SA. However, SA was unable to adsorb Cu (II ions. SA exhibited the lower WC and SW values as compared to SC which suggested an improved hydrophobicity after the modification. This study has shown that hydrophobicity can be improved in cellulose via surface modification.

  7. Investigation and characterization of oxidized cellulose and cellulose nanofiber films

    Science.gov (United States)

    Yang, Han

    Over the last two decades, a large amount of research has focused on natural cellulose fibers, since they are "green" and renewable raw materials. Recently, nanomaterials science has attracted wide attention due to the large surface area and unique properties of nanoparticles. Cellulose certainly is becoming an important material in nanomaterials science, with the increasing demand of environmentally friendly materials. In this work, a novel method of preparing cellulose nanofibers (CNF) is being presented. This method contains up to three oxidation steps: periodate, chlorite and TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) oxidation. The first two oxidation steps are investigated in the first part of this work. Cellulose pulp was oxidized to various extents by a two step-oxidation with sodium periodate, followed by sodium chlorite. The oxidized products can be separated into three different fractions. The mass ratio and charge content of each fraction were determined. The morphology, size distribution and crystallinity index of each fraction were measured by AFM, DLS and XRD, respectively. In the second part of this work, CNF were prepared and modified under various conditions, including (1) the introduction of various amounts of aldehyde groups onto CNF by periodate oxidation; (2) the carboxyl groups in sodium form on CNF were converted to acid form by treated with an acid type ion-exchange resin; (3) CNF were cross-linked in two different ways by employing adipic dihydrazide (ADH) as cross-linker and water-soluble 1-ethyl-3-[3-(dimethylaminopropyl)] carbodiimide (EDC) as carboxyl-activating agent. Films were fabricated with these modified CNF suspensions by vacuum filtration. The optical, mechanical and thermo-stability properties of these films were investigated by UV-visible spectrometry, tensile test and thermogravimetric analysis (TGA). Water vapor transmission rates (WVTR) and water contact angle (WCA) of these films were also studied.

  8. Polyimide Cellulose Nanocrystal Composite Aerogels

    Science.gov (United States)

    Nguyen, Baochau N.; Meador, Mary Ann; Rowan, Stuart; Cudjoe, Elvis; Sandberg, Anna

    2014-01-01

    Polyimide (PI) aerogels are highly porous solids having low density, high porosity and low thermal conductivity with good mechanical properties. They are ideal for various applications including use in antenna and insulation such as inflatable decelerators used in entry, decent and landing operations. Recently, attention has been focused on stimuli responsive materials such as cellulose nano crystals (CNCs). CNCs are environmentally friendly, bio-renewable, commonly found in plants and the dermis of sea tunicates, and potentially low cost. This study is to examine the effects of CNC on the polyimide aerogels. The CNC used in this project are extracted from mantle of a sea creature called tunicates. A series of polyimide cellulose nanocrystal composite aerogels has been fabricated having 0-13 wt of CNC. Results will be discussed.

  9. Nano-cellulose derived bioplastic biomaterial data for vehicle bio-bumper from banana peel waste biomass

    OpenAIRE

    Sharif Hossain, A.B.M.; Ibrahim, Nasir A.; AlEissa, Mohammed Saad

    2016-01-01

    The innovative study was carried out to produce nano-cellulose based bioplastic biomaterials for vehicle use coming after bioprocess technology. The data show that nano-cellulose particle size was 20 nm and negligible water absorption was 0.03% in the bioplastic. Moreover, burning test, size and shape characterizations, spray coating dye, energy test and firmness of bioplastic have been explored and compared with the standardization of synthetic vehicle plastic bumper following the American S...

  10. Adsorption, desorption, and removal of polymeric nanomedicine on and from cellulose surfaces: effect of size.

    Science.gov (United States)

    Zhang, Ming; Akbulut, Mustafa

    2011-10-18

    The increased production and commercial use of nanoparticulate drug delivery systems combined with a lack of regulation to govern their disposal may result in their introduction to soils and ultimately into groundwater systems. To better understand how such particles interact with environmentally significant interfaces, we study the adsorption, desorption, and removal behavior of poly(ethylene glycol)-based nanoparticulate drug delivery systems on and from cellulose, which is the most common organic compound on Earth. It is shown that such an adsorption process is only partially reversible, and most of the adsorbate particles do not desorb from the cellulose surface even upon rinsing with a large amount of water. The rate constant of adsorption decreases with increasing particle size. Furthermore, hydrodynamic forces acting parallel to the surfaces are found to be of great importance in the context of particle dynamics near the cellulose surface, and ultimately responsible for the removal of some fraction of particles via rolling or sliding. As the particle size increases, the removal rates of the particles increase for a given hydrodynamical condition. © 2011 American Chemical Society

  11. Conductance phenomena in microcrystalline cellulose

    Science.gov (United States)

    Nilsson, M.

    2006-02-01

    We have investigated the conduction phenomena in compacted tablets of cellulose with varying relative humidity (RH) with techniques such as Low Frequency Dielectric Spectroscopy (LFDS) and Transient Current (TC) at room temperature. Two exponential decaying regions in the transient current measurements indicate two ionic species contributing to the conduction mechanism. A high power-law exponent of 9 for the conductance with moisture content has been found. The mobility initially decreases with RH up to monolayer coverage, and further water vapor increases the mobility, indicating a blocking of available positions for the charge carrier ions. When the amount of water molecules present in the tablet increases one order of magnitude, the number of charge carriers increases 5-6 orders of magnitude, suggesting a transition from a power-law increase to a linear effective medium theory for the conduction. The charge carrier dependence on RH suggests that a percolating network of water molecules adsorbed to 6-OH units on the cellulose chain span through the sample. The conductivity mechanisms in cellulose are still not clear.

  12. Preparation and Characterization of Cellulose Nanocrystals from the Bio-ethanol Residuals

    Directory of Open Access Journals (Sweden)

    Lanxing Du

    2017-02-01

    Full Text Available This study was to explore the conversion of low-cost bio-residuals into high value-added cellulose nanocrystals. Two enzymatic hydrolyzed residuals (i.e., HRMMW and HRSPW were collected from two different bio-ethanol producing processes—hydrolyzing medium-milled wood (MMW and hydrolyzing acid sulfite pretreated wood (SPW, respectively. The results showed that both residuals contained over 20 wt % glucan with a crystallinity of about 30%, confirming the existence of cellulose in a well-organized structure in two bio-residuals. The cellulose nanocrystals (CNCs were successfully extracted by first bleaching the hydrolyzed residuals to remove lignin and then hydrolyzing them with sulfuric acid. The resulting CNCs displayed the flow birefringence under two crossed polarizers. Compared with CNCs from microfibrillated cellulose (CNCMCC, HRMMW and its resulted CNC present the smallest particle size and aspect ratio. CNCMCC had the larger particle size, aspect ratio, and higher z-potential value, CNCSPW presented a similar morphology to CNCMCC, and had the largest aspect ratio. The CNCMCC enhanced its high crystallinity to 85.5%. However, CNCMMW and CNCSPW had a better thermal stability and higher activation energy as well as onset temperature and maximum decomposition temperature. As a result, the CNCs from bio-ethanol residuals are valued and promising cellulose nanoparticle resources.

  13. Preparation and Characterization of Cellulose Nanocrystals from the Bio-ethanol Residuals.

    Science.gov (United States)

    Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

    2017-02-23

    This study was to explore the conversion of low-cost bio-residuals into high value-added cellulose nanocrystals. Two enzymatic hydrolyzed residuals (i.e., HR MMW and HR SPW ) were collected from two different bio-ethanol producing processes-hydrolyzing medium-milled wood (MMW) and hydrolyzing acid sulfite pretreated wood (SPW), respectively. The results showed that both residuals contained over 20 wt % glucan with a crystallinity of about 30%, confirming the existence of cellulose in a well-organized structure in two bio-residuals. The cellulose nanocrystals (CNCs) were successfully extracted by first bleaching the hydrolyzed residuals to remove lignin and then hydrolyzing them with sulfuric acid. The resulting CNCs displayed the flow birefringence under two crossed polarizers. Compared with CNCs from microfibrillated cellulose (CNC MCC ), HR MMW and its resulted CNC present the smallest particle size and aspect ratio. CNC MCC had the larger particle size, aspect ratio, and higher z-potential value, CNC SPW presented a similar morphology to CNC MCC , and had the largest aspect ratio. The CNC MCC enhanced its high crystallinity to 85.5%. However, CNC MMW and CNC SPW had a better thermal stability and higher activation energy as well as onset temperature and maximum decomposition temperature. As a result, the CNCs from bio-ethanol residuals are valued and promising cellulose nanoparticle resources.

  14. Chemo-catalytic valorization of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Palkovits, R. [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie

    2012-07-01

    Cellulose can be utilized as carbon source for the production of novel platform molecules as well as fuel motifs. Promising transformation strategies cover the hydrolytic hydrogenation or hydrogenolysis of cellulose to sugar alcohols, the hydrolysis of cellulose to glucose followed by dehydration to 5-hydroxymethylfurfural or levulinic acid and the further hydrogenation of levulinic acid to {gamma}-valerolactone. Main challenges result from the high degree of functionalization of cellulosic feedstocks. In line, processes are carried out in liquid phase utilizing rather polar solvents and aiming for a tailored defunctionalisation of these oxygen rich compounds. Consequently, such transformations require novel strategies concerning the development of suitable catalysts and appropriate process concepts. (orig.)

  15. Liquid crystalline solutions of cellulose in phosphoric acid for preparing cellulose yarns

    NARCIS (Netherlands)

    Boerstoel, H.

    2006-01-01

    The presen thesis describes a new process for manufacturing high tenacity and high modulus cellulose yarns. A new direct solvent for cellulose has been discovered, leading to liquid crystalline solutions. This new solvent, superphosphoric acid, rapidly dissolves cellulose. These liquid crystalline

  16. Nano-tubular cellulose for bioprocess technology development.

    Science.gov (United States)

    Koutinas, Athanasios A; Sypsas, Vasilios; Kandylis, Panagiotis; Michelis, Andreas; Bekatorou, Argyro; Kourkoutas, Yiannis; Kordulis, Christos; Lycourghiotis, Alexis; Banat, Ibrahim M; Nigam, Poonam; Marchant, Roger; Giannouli, Myrsini; Yianoulis, Panagiotis

    2012-01-01

    Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC) justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation). The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator). Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

  17. Radiation synthesis of silver nano- and microparticles in cellulose fibres

    International Nuclear Information System (INIS)

    Chmielewska, D.K.; Sartowska, B.; Starosta, W.; Walo, M.

    2010-01-01

    Polymer nanocomposites containing metal nanoparticles have attracted a great interest due to their unique chemical and physical properties. 'Green' chemistry promotes application of natural fibers in such structures, among them cellulose is one of the most frequently used. However, cellulose fabric have ability to absorb moisture, so under certain conditions of humidity and temperature they can be subjected to microbial attack. One of the most popular and best known antibacterial agents is silver, which serves as a potential antibacterial material acting against an exceptionally broad spectrum of bacteria including activity against antibiotic-resistant bacteria. Silver nanoparticles (Ag NPs) were grown at the cellulose fibers surface by direct reduction of AgNO 3 with electron beam (EB) application. Nanocomposites obtained according to the method described in the text were investigated with X-ray diffraction (XRD), scanning electron microscope with back-scattered electrons detector (SEM-BSE) and energy dispersive spectroscopy (EDS) as well as thermogravimetric analysis (TGA) in order to determine influence of different size silver particles on fibers thermal properties. (authors)

  18. Nano-tubular cellulose for bioprocess technology development.

    Directory of Open Access Journals (Sweden)

    Athanasios A Koutinas

    Full Text Available Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation. The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator. Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

  19. High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose

    KAUST Repository

    Ali, Ola

    2013-05-01

    Regenerated cellulose (RC) membranes are extensively used in medical and pharmaceutical separation processes due to their biocompatibility, low fouling tendency and solvent resistant properties. They typically possess ultrafiltration and microfiltration separation characteristics, but recently, there have been attempts to widen their pool of applications in nanofiltration processes. In this work, a novel method for preparing high performance composite RC membranes was developed. These membranes reveal molecular weight cut-offs (MWCO) of less than 250 daltons, which possibly put them ahead of all commercial RC membranes and in competition with high performance nanofiltration membranes. The membranes were prepared by acidic hydrolysis of dip-coated trimethylsilyl cellulose (TMSC) films. TMSC, with a degree of silylation (DS) of 2.8, was prepared from microcrystalline cellulose by reaction with hexamethyldisilazane under the homogeneous conditions of LiCl/DMAC solvent system. Effects of parameters, such as coating solution concentration and drying rates, were investigated. It was concluded that higher TMSC concentrations as well as higher solvent evaporation rates favor better MWCOs, mainly due to increase in the selective layer thickness. Successful cross-linking of prepared membranes with glyoxal solutions, in the presence of boric acid as a catalyst, resulted in MWCOs less than 250 daltons. The suitability of this crosslinking reaction for large scale productions was already proven in the manufacturing of durable-press fabrics. For us, the inexpensive raw materials as well as the low reaction times and temperatures were of interest. Moreover, the non-toxic nature of glyoxal is a key advantage in medical and pharmaceutical applications. The membranes prepared in this work are strong candidates for separation of small organic solutes from organic solvents streams in pharmaceutical industries. Their hydrophilicity, compared to typical nanofiltration membranes, offer

  20. Cellulose-Hemicellulose Interactions at Elevated Temperatures Increase Cellulose Recalcitrance to Biological Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Ashutosh [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Himmel, Michael E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kumar, Rajeev [University of California, Riverside; Oak Ridge National Laboratory; ; Smith, Micholas Dean [Oak Ridge National Laboratory; University of Tennessee; Petridis, Loukas [Oak Ridge National Laboratory; University of Tennessee; Ong, Rebecca G. [Michigan Technological University; Cai, Charles M. [University of California, Riverside; Oak Ridge National Laboratory; Balan, Venkatesh [University of Houston; Dale, Bruce E. [Michigan State University; Ragauskas, Arthur J. [Oak Ridge National Laboratory; University of Tennessee; Smith, Jeremy C. [Oak Ridge National Laboratory; University of Tennessee; Wyman, Charles E. [University of California, Riverside; Oak Ridge National Laboratory

    2018-01-23

    It has been previously shown that cellulose-lignin droplets' strong interactions, resulting from lignin coalescence and redisposition on cellulose surface during thermochemical pretreatments, increase cellulose recalcitrance to biological conversion, especially at commercially viable low enzyme loadings. However, information on the impact of cellulose-hemicellulose interactions on cellulose recalcitrance following relevant pretreatment conditions are scarce. Here, to investigate the effects of plausible hemicellulose precipitation and re-association with cellulose on cellulose conversion, different pretreatments were applied to pure Avicel(R) PH101 cellulose alone and Avicel mixed with model hemicellulose compounds followed by enzymatic hydrolysis of resulting solids at both low and high enzyme loadings. Solids produced by pretreatment of Avicel mixed with hemicelluloses (AMH) were found to contain about 2 to 14.6% of exogenous, precipitated hemicelluloses and showed a remarkably much lower digestibility (up to 60%) than their respective controls. However, the exogenous hemicellulosic residues that associated with Avicel following high temperature pretreatments resulted in greater losses in cellulose conversion than those formed at low temperatures, suggesting that temperature plays a strong role in the strength of cellulose-hemicellulose association. Molecular dynamics simulations of hemicellulosic xylan and cellulose were found to further support this temperature effect as the xylan-cellulose interactions were found to substantially increase at elevated temperatures. Furthermore, exogenous, precipitated hemicelluloses in pretreated AMH solids resulted in a larger drop in cellulose conversion than the delignified lignocellulosic biomass containing comparably much higher natural hemicellulose amounts. Increased cellulase loadings or supplementation of cellulase with xylanases enhanced cellulose conversion for most pretreated AMH solids; however, this approach

  1. [Terahertz and Infrared Spectroscopic Investigation of Cellulose].

    Science.gov (United States)

    Qiu, Guo-hua; Zhang, Le; Shentu, Nan-ying

    2016-03-01

    To investigate the Terahertz's application prospect, corn, wheat husk and reed were used to detect their Terahertz Time Domain Spectroscopy, and be compared with that of cellulose powder. The experimental results show that all of their absorption peaks exist at 1.75, 1.62, 1.1, and 0.7 THz. Absorption intensity of cellulose powder, corn, wheat husk and reed were compared in some frequencies points. It finds that corn, wheat husk and reed have higher absorption intensity than cellulose powder in early frequency domain. However, absorption intensity of cellulose powder is the strongest at 1.62 THz. Cellulose content in corn, wheat husk and reed were detected by using the method of chemical analysis. The peaks of absorption coefficient are related to their cellulose content at this frequency. It shows that plant cellulose occur lattice vibration in the frequency. Deformation, bending, flexing, and other changes appear to their functional keys. Quantum chemical calculation was carried out by using density functional theory to cellulose and the structure diagram of cellulose molecular formula was obtained. It also finds some absorption peaks exist at 0.7, 1.1, and 1.75 THz. Characterization of cellulose clusters mainly includes CH2, OH, CH, and so on. Glucose hydroxyl radical on the ring is active in the cellulose chain. Where hydroxyl related chemical reaction can occur, Hydroxyl can also be integrated into the intermolecular and intramolecular hydrogen bond. Terahertz wave can promote hydrogen bond vibration. This kind of vibration is weak in the intermolecular interaction. The vibration and rotating happen in dipole transition. The crystal lattice rotates and is absorptive in low frequency, and large molecular skeleton vibrates. All of them can show different intensity and position of the absorption peak in the terahertz band. Corn and cellulose were analyzed by infrared spectrum. The reverse and vibration mode of cellulose was discussed. The absorption peak is

  2. Pyrolytic sugars from cellulosic biomass

    Science.gov (United States)

    Kuzhiyil, Najeeb

    Sugars are the feedstocks for many promising advanced cellulosic biofuels. Traditional sugars derived from starch and sugar crops are limited in their availability. In principle, more plentiful supply of sugars can be obtained from depolymerization of cellulose, the most abundant form of biomass in the world. Breaking the glycosidic bonds between the pyranose rings in the cellulose chain to liberate glucose has usually been pursued by enzymatic hydrolysis although a purely thermal depolymerization route to sugars is also possible. Fast pyrolysis of pure cellulose yields primarily levoglucosan, an anhydrosugar that can be hydrolyzed to glucose. However, naturally occurring alkali and alkaline earth metals (AAEM) in biomass are strongly catalytic toward ring-breaking reactions that favor formation of light oxygenates over anhydrosugars. Removing the AAEM by washing was shown to be effective in increasing the yield of anhydrosugars; but this process involves removal of large amount of water from biomass that renders it energy intensive and thereby impractical. In this work passivation of the AAEM (making them less active or inactive) using mineral acid infusion was explored that will increase the yield of anhydrosugars from fast pyrolysis of biomass. Mineral acid infusion was tried by previous researchers, but the possibility of chemical reactions between infused acid and AAEM in the biomass appears to have been overlooked, possibly because metal cations might be expected to already be substantially complexed to chlorine or other strong anions that are found in biomass. Likewise, it appears that previous researchers assumed that as long as AAEM cations were in the biomass, they would be catalytically active regardless of the nature of their complexion with anions. On the contrary, we hypothesized that AAEM can be converted to inactive or less active salts using mineral acids. Various biomass feedstocks were infused with mineral (hydrochloric, nitric, sulfuric and

  3. Synthesis of Nanocrystalline Cellulose Stabilized Copper Nanoparticles

    Directory of Open Access Journals (Sweden)

    Aminu Musa

    2016-01-01

    Full Text Available A chemical reduction method was employed for the synthesis of copper nanoparticles stabilized by nanocrystalline cellulose (NCC using different concentrations of copper salt in aqueous solution under atmospheric air. CuSO4·5H2O salt and hydrazine were used as metal ion precursor and reducing agent, respectively. Ascorbic acid and aqueous NaOH were also used as an antioxidant and a pH moderator, respectively. The number of CuNPs increased with increasing concentration of the precursor salt. The formation of copper nanoparticles stabilized by NCC (CuNPs@NCC was investigated by UV-visible spectroscopy (UV-vis, where the surface absorption maximum was observed at 590 nm. X-ray diffraction (XRD analysis showed that the CuNPs@NCC are of a face-centered cubic structure. Moreover, the morphology of the CuNPs@NCC was investigated using transmission electron microscope (TEM and field emission scanning electron microscope (FESEM, which showed well-dispersed CuNPs with an average particle size less than 4 nm and the shape of CuNPs was found to be spherical. Energy dispersive X-ray spectroscope (EDS also confirmed the presence of CuNPs on the NCC. The results demonstrate that the stability of CuNPs decreases with an increasing concentration of the copper ions.

  4. Photoresponsive cellulose fibers by surface modification with multifunctional cellulose derivatives.

    Science.gov (United States)

    Grigoray, Olga; Wondraczek, Holger; Heikkilä, Elina; Fardim, Pedro; Heinze, Thomas

    2014-10-13

    Eucalyptus bleached kraft pulp fibers were modified by adsorption of novel bio-based multifunctional cellulose derivatives in order to generate light responsive surfaces. The cellulose derivatives used were decorated with both cationic groups (degree of substitution, DS of 0.34) and photoactive groups (DS of 0.11 and 0.37). The adsorption was studied by UV-vis spectroscopy, surface plasmon resonance (SPR) and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The adsorption isotherms followed the Freundlich model and it turned out that the main driving force for the adsorption was electrostatic interaction. Moreover, strong indications for hydrophobic interactions between the fibers and the derivatives and the derivatives themselves were found. ToF-SIMS imaging revealed an even distribution of the derivatives on the fiber surfaces. The modified fibers underwent fast photocrosslinking under UV-irradiation as demonstrated by light absorbance and fluorescence measurements. Thus, our results proved that the modified fibers exhibited light-responsive properties and can potentially be used for the manufacture of smart bio-based materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. The oro-ileal transit of cellulose.

    Science.gov (United States)

    Oyama, T; Fukuda, S; Shimoyama, T; Takahashi, I; Umeda, T; Danjo, K; Saito, D; Chinda, D; Sakamoto, J; Nakaji, S

    2008-11-01

    The effects of cellulose and the interindividual variations on the transit time in the small intestine remain unclear, but no previous study has to date taken these factors into sufficient consideration. We assessed the oro-ileal transit time and the recovery percentage of cellulose in the terminal ileum looking at interindividual variations. Seven healthy males received 100 mL of a dietary fiber-free basal diet with 5 g cellulose and 5 g of polyethylene glycol 4000. The ileal contents were aspirated every 30 min via an experimental tube placed in the terminal ileum to assess the oro-ileal transit time and the recovery percentage of cellulose. The mean percentage (with standard deviation) of the amounts of cellulose collected in the terminal ileum was 98.4%+/- 16.5% (ranging from 67.4% to 114.5%) with a coefficient variation of 16.8%. The average times (in hours) taken for 20%, 40%, 60%, and 80% of cellulose to reach the terminal ileum were 5.5 +/- 1.1, 6.7 +/- 0.7, 8.5 +/- 1.3, and 8.8 +/- 1.2, respectively, with large interindividual variations. In conclusion, the averaged recovery percentage of cellulose in the terminal ileum was approximately 100%, in accordance with the present generally accepted definition of dietary fiber. However, there were large interindividual variations in the oro-ileal transit time and the percentage of cellulose recovered.

  6. Book review: "cellulose science and technology"

    Science.gov (United States)

    Cellulose Science and Technology” by Jean-Luc Wertz, Olivier Bédué and Jean P. Mercier is a fairly comprehensive, up-to-date introduction to many areas of cellulose science. Their summary of a vast and often controversial literature is reasonably comprehensive. It requires little background to re...

  7. Some Physical Characteristics of Microcrystalline Cellulose ...

    African Journals Online (AJOL)

    Purpose: The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. This study aimed at evaluating the physical characteristics of microcrystalline cellulose (CP-MCC), obtained from the raw cotton of Cochlospermum planchonii. Methods: CP-MCC was obtained from the ...

  8. Characterization of cellulose nanofibrillation by micro grinding

    Science.gov (United States)

    Sandeep S. Nair; J.Y. Zhu; Yulin Deng; Arthur J. Ragauskas

    2014-01-01

    A fundamental understanding of the morphological development of cellulose fibers during fibrillation using micro grinder is very essential to develop effective strategies for process improvement and to reduce energy consumption. We demonstrated some simple measures for characterizing cellulose fibers fibrillated at different fibrillation times through the grinder. The...

  9. Isolation and characterization of microcrystalline cellulose obtained ...

    African Journals Online (AJOL)

    In this study, microcrystalline cellulose, coded MCC-PNF, was obtained from palm nut (Elaeis guineensis) fibres. MCC-PNF was examined for its physicochemical and powder properties. The powder properties of MCC-PNF were compared to those of the best commercial microcrystalline cellulose grade, Avicel PH 101.

  10. Cellulose, een eindeloze bron van mogelijkheden

    NARCIS (Netherlands)

    Keijsers, E.R.P.; Dam, van J.E.G.; Yilmaz, G.

    2011-01-01

    Vanwege de grote diversiteit van potentiële cellulose bronnen en de grote verschillen in kwalitatieve eigenschappen en samenstelling van deze cellulose types is het van belang in kaart te brengen voor welke toepassingen de verschillende grondstoffen het meest geschikt zijn. Voor het opstellen van

  11. Diffraction from nonperiodic models of cellulose crystals

    Science.gov (United States)

    Powder and fiber diffraction patterns were calculated for model cellulose crystallites with chains 20 glucose units long. Model sizes ranged from four chains to 169 chains, based on cellulose I' coordinates, and were subjected to various combinations of energy minimization and molecular dynamics (M...

  12. Modelling the elastic properties of cellulose nanopaper

    DEFF Research Database (Denmark)

    Mao, Rui; Goutianos, Stergios; Tu, Wei

    2017-01-01

    The elastic modulus of cellulose nanopaper was predicted using a two-dimensional (2D) micromechanical fibrous network model. The elastic modulus predicted by the network model was 12 GPa, which is well within the range of experimental data for cellulose nanopapers. The stress state in the network...

  13. Potentials of cellulosic wastes in media formulation

    African Journals Online (AJOL)

    AJB SERVER

    2007-02-05

    Feb 5, 2007 ... Potential use of cellulosic wastes as carbon and energy sources in selective media formulations was investigated. Two agar media, Czapek-Dox and Sabouraud's agar, were modified by substituting their carbon sources with cellulose, sawdust and sugarcane pulps. Then, two fungi; Aspergillus niger.

  14. Molecular modeling of amorphous and crosslinked cellulose

    Science.gov (United States)

    Chen, Wei

    2001-07-01

    Structure-property relationships in cellulose crosslinked with both conventional and elastomeric crosslinking agents were successfully calculated using molecular modeling. The observed yielding for these amorphous cellulose models, which occurred at approximately 8% strain according to the calculated stress-strain relationship, is due to the disruption of hydrogen bonds, the secondary crosslinks, between cellulose chain segments. Crosslinks hold cellulose chain segments together and block chain slippage to give cellulose fibers a higher initial modulus and better elastic response. However, these crosslinks restrict chain movement so that stress is concentrated in regions of the structure and cavities are formed and developed in these regions of the models, which correlate to final fiber failure. The flexibility and response to applied external force for some potential crosslink structures were examined by molecular modeling. These molecules, which have small energy differences between conformational states, are highly coiled and have small mean end-to-end distances (accounting for 40% to 50% of the length of their fully extended chains). The presence of oxygen atoms in the backbone along with asymmetric non-polar side groups, such as methyl groups, can greatly reduce the energy difference and the energy barrier between conformational states and can thus make chains highly coiled and easy to be extended. Decane crosslinks introduced more freedom to cellulose chain segments but didn't improve the deformation recovery in cellulose models. Conformational transitions were observed in decane crosslinks during deformation. Cellulose models crosslinked with poly(propylene oxide) pentamers or with the N-methyl substituted peptide pentamers show good deformation recovery without affecting the breaking strain. Both crosslinks didn't significantly change the initial modulus and the yielding behavior of cellulose. No conformation transitions were observed in these crosslinks

  15. Looking at hydrogen bonds in cellulose.

    Science.gov (United States)

    Nishiyama, Yoshiharu; Langan, Paul; Wada, Masahisa; Forsyth, V Trevor

    2010-11-01

    A series of cellulose crystal allomorphs has been studied using high-resolution X-ray and neutron fibre diffraction to locate the positions of H atoms involved in hydrogen bonding. One type of position was always clearly observed in the Fourier difference map (F(d)-F(h)), while the positions of other H atoms appeared to be less well established. Despite the high crystallinity of the chosen samples, neutron diffraction data favoured some hydrogen-bonding disorder in native cellulose. The presence of disorder and a comparison of hydrogen-bond geometries in different allomorphs suggests that although hydrogen bonding may not be the most important factor in the stabilization of cellulose I, it is essential for stabilizing cellulose III, which is the activated form, and preventing it from collapsing back to the more stable cellulose I.

  16. Development of composites of polycaprolactone with cellulose

    International Nuclear Information System (INIS)

    Aguiar, V.O.; Marques, M.F.V.

    2015-01-01

    In the present work, alkaline followed by an acid treatment were performed in plant sources of curaua and jute fibers to remove the amorphous portion and to aid fibrillation. Using the technique of X-ray diffraction it was observed that the chemical treatments led to a better organization of cellulose microfibrils and, consequently, the increase in their crystallinity index. Using the thermogravimetric analysis it was noted a slight decrease in thermal stability of the chemically treated cellulose fibers, however it did not impairs its use as filler in the polymer matrix. Through the SEM micrographs it was observed that the chemical treatment reduced the dimensions of the fibers in natura. Polycaprolactone composite was prepared in a twin-screw extruder at different amounts for several cellulose sources (those obtained from vegetable fibers, curaua and jute, commercial cellulose and amorphous cellulose) at and maintaining the process time and temperature constant. (author)

  17. Functional Analysis of Cellulose and Xyloglucan in the Walls of Stomatal Guard Cells of Arabidopsis1[OPEN

    Science.gov (United States)

    Rui, Yue; Anderson, Charles T.

    2016-01-01

    Stomatal guard cells are pairs of specialized epidermal cells that control water and CO2 exchange between the plant and the environment. To fulfill the functions of stomatal opening and closure that are driven by changes in turgor pressure, guard cell walls must be both strong and flexible, but how the structure and dynamics of guard cell walls enable stomatal function remains poorly understood. To address this question, we applied cell biological and genetic analyses to investigate guard cell walls and their relationship to stomatal function in Arabidopsis (Arabidopsis thaliana). Using live-cell spinning disk confocal microscopy, we measured the motility of cellulose synthase (CESA)-containing complexes labeled by green fluorescent protein (GFP)-CESA3 and observed a reduced proportion of GFP-CESA3 particles colocalizing with microtubules upon stomatal closure. Imaging cellulose organization in guard cells revealed a relatively uniform distribution of cellulose in the open state and a more fibrillar pattern in the closed state, indicating that cellulose microfibrils undergo dynamic reorganization during stomatal movements. In cesa3je5 mutants defective in cellulose synthesis and xxt1 xxt2 mutants lacking the hemicellulose xyloglucan, stomatal apertures, changes in guard cell length, and cellulose reorganization were aberrant during fusicoccin-induced stomatal opening or abscisic acid-induced stomatal closure, indicating that sufficient cellulose and xyloglucan are required for normal guard cell dynamics. Together, these results provide new insights into how guard cell walls allow stomata to function as responsive mediators of gas exchange at the plant surface. PMID:26729799

  18. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Donaldson, T.L.; Lee, D.D.

    1984-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 7 references, 5 figures, 1 table

  19. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1985-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of low-level radioactive cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work has been completed using a 75-L digester to verify rates and conversions obtained at the bench scale. Start-up and operating procedures have been developed, and effluent was generated for characterization and disposal studies. Three runs using batch and fed-batch conditions were made lasting 36, 90, and 423 d. Solids solubilization rates and gas production rates averaged approximately 1.8 g cellulose per L of reactor per d and 1.2 L of off-gas per L reactor per d. Greater than 80% destruction of the volatile suspended solids was obtained. A simple dynamic process model was constructed to aid in process design and for use in process monitoring and control of a large-scale digester

  20. Cytocompatible cellulose hydrogels containing trace lignin

    Energy Technology Data Exchange (ETDEWEB)

    Nakasone, Kazuki; Kobayashi, Takaomi, E-mail: takaomi@nagaoakut.ac.jp

    2016-07-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12 h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43 N/mm{sup 2} and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

  1. Environmentally friendly procedure for in-situ coating of regenerated cellulose fibres with silver nanoparticles.

    Science.gov (United States)

    Pivec, Tanja; Hribernik, Silvo; Kolar, Mitja; Kleinschek, Karin Stana

    2017-05-01

    This study introduces a novel green in-situ procedure for introduction of silver nanoparticles (Ag NPs) on and into cellulose fibres in a three-stage process. First-stage of the process includes the activation of cellulose fibres in alkaline solution, followed by reduction of silver nitrate to Ag NPs in the second stage, while the last stage of process involves washing and neutralization of fibres. Efficiency of the method towards incorporation of silver particles into the fibres' internal structure was characterized; the coatings' morphology and determination of spatial presence of Ag particles were imagining by the scanning electron microscopy and accompanying energy dispersive x-ray spectroscopy analysis; prepared fibres have superior durability of particles' coating against washing and excellent antimicrobial activity even after 20 washing cycles. Additionally, the water retention of silver treated fibres was improved, while the mechanical properties were not significantly impaired. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Cellulose Nanocrystals Obtained from Rice By-Products and Their Binding Potential to Metallic Ions

    Directory of Open Access Journals (Sweden)

    Vanessa L. Albernaz

    2015-01-01

    Full Text Available The present study aimed to develop and optimize a method to obtain cellulose nanocrystals from the agricultural by-products rice husk and straw and to evaluate their electrostructural modifications in the presence of metallic ions. First, different particle formation conditions and routes were tested and analyzed by spectrophotometry, dynamic light scattering (DLS, and Zeta potential measurements. Then, electrostructural effects of ions Na(I, Cd(II, and Al(III on the optimized nanoparticles were analyzed by atomic force microscopy (AFM, scanning electron microscopy (SEM, and electrical conductivity (EC assessments. The produced cellulose nanocrystals adopted a rod-like shape. AFM height distribution and EC data indicated that the nanocrystals have more affinity in binding with Na(I > Al(III > Cd(II. These data suggest that the use of these cellulose nanocrystals in the bioremediation field is promising, both in metal sorption from wastewater and as an alternative for water desalination.

  3. Thermally induced gel from cellulose/NaOH/PEG solution: preparation, characterization and mechanical properties

    Science.gov (United States)

    Wan, Caichao; Lu, Yun; Jin, Chunde; Sun, Qingfeng; Li, Jian

    2015-04-01

    In this paper, we reported a thermally induced gel with strong mechanical properties prepared from cellulose/NaOH/PEG aqueous solution following the procedures of dissolution, heating and freeze-drying. The as-prepared gel showed undeveloped networks composed of cross-linked fiber aggregations tightly coated with plenty of NaOH·H2O and PEG-aggregated fine particles, which led to the significant enhancement of thermal stability and the disappearance of the original cellulose crystalline structures. Furthermore, the elastic modulus, yield stress and toughness of the mechanically strong gel were measured to be up to 3,210, 325 kPa and 389 kJ m-3, respectively, comparable to those of cross-linked polymer gel materials with strong mechanical strength such as the microfibrillated cellulose aerogels and the three-dimensional architectures of graphene hydrogels.

  4. Nano-cellulose derived bioplastic biomaterial data for vehicle bio-bumper from banana peel waste biomass

    Directory of Open Access Journals (Sweden)

    A.B.M. Sharif Hossain

    2016-09-01

    Full Text Available The innovative study was carried out to produce nano-cellulose based bioplastic biomaterials for vehicle use coming after bioprocess technology. The data show that nano-cellulose particle size was 20 nm and negligible water absorption was 0.03% in the bioplastic. Moreover, burning test, size and shape characterizations, spray coating dye, energy test and firmness of bioplastic have been explored and compared with the standardization of synthetic vehicle plastic bumper following the American Society for Testing and Materials (ASTM. Tensile test was observed 120 MPa/kg m3. In addition to that pH and cellulose content were found positive in the bioplastic compared to the synthetic plastic. Chemical tests like K, CO3, Cl2, Na were determined and shown positive results compared to the synthetic plastic using the EN-14214 (European Norm standardization. Keywords: Nano-celluloses, Biopolymer, Banana peel waste, Biobumper

  5. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  6. Surface modification of cellulose by PCL grafts

    International Nuclear Information System (INIS)

    Paquet, Olivier; Krouit, Mohammed; Bras, Julien; Thielemans, Wim; Belgacem, Mohamed Naceur

    2010-01-01

    Two cellulosic substrates (microcrystalline cellulose, MCC, and bleached kraft softwood pulps, BSK) were grafted by polycaprolactone (PCL) chains with different molecular weights, following a three-step procedure using non-swelling conditions in order to limit the reaction to their surface. First, one of the two OH PCL ends was blocked by phenyl isocyanate and the reaction product (adduct 1) was subsequently reacted with 2,4-toluene diisocyanate (adduct 2) to provide it with an NCO function, capable of reacting with cellulose. The ensuing PCL-grafted cellulosic materials were characterized by weight gain, elemental analysis, contact angle measurements, attenuated total reflexion-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and biodegradation tests. The modification was proven to occur by the presence of nitrogen atoms in the elemental analysis tests and XPS spectra of modified and soxhlet-extracted cellulose. The contact angle measurements have also shown that the surface became as hydrophobic as PCL itself. The polar component of the surface energy of cellulosic substrates before treatment was found to be about 32 and 10 mJ m -2 , for MCC and BSK, respectively. This value vanished to practically zero after grafting with different PCLs. The strategy proposed in the present work is original since, to the best of our knowledge, this paper reports for the first time the chemical 'grafting onto' of the cellulose surface by PCL macromolecular structures, with the aim of obtaining fibre-matrix co-continuous fully sustainable and biodegradable composite materials.

  7. Enhancement of Cellulose Degradation by Cattle Saliva

    Science.gov (United States)

    Seki, Yasutaka; Kikuchi, Yukiko; Kimura, Yoshihiro; Yoshimoto, Ryo; Takahashi, Masatoshi; Aburai, Kenichi; Kanai, Yoshihiro; Ruike, Tatsushi; Iwabata, Kazuki; Sugawara, Fumio; Sakai, Hideki; Abe, Masahiko; Sakaguchi, Kengo

    2015-01-01

    Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale. PMID:26402242

  8. Effect of functionalization on the adsorption capacity of cellulose for the removal of methyl violet.

    Science.gov (United States)

    Musyoka, Stephen Makali; Mittal, Hemant; Mishra, Shivani B; Ngila, Jane Catherine

    2014-04-01

    In this research paper a comparative study has been carried out for the removal of methyl violet dye using unfunctionalized and functionalized cellulose. The functionalization was achieved through esterification of cellulose with furan-2,5-dione. The functionalization of the cellulose was evidenced using BET, FT-IR, SEM and TGA. The adsorption isotherm data was fitted using different isotherm models like Langmuir, Freundlich, Temkin, Flory-Huggins and Dubinin-Kaganer-Radushkevich models and found to follow Langmuir and Temkin isotherm models with high value of correlation coefficients. Functionalized cellulose (106.38 mg g(-1)) showed higher dye removal capability than unfunctionalized cellulose (43.668 mg g(-1)). The kinetics of adsorption was investigated using pseudo first order, second order, Elovich, liquid film diffusion and intra-particle diffusion models. The mechanism of adsorption was found to follow pseudo second order rate equation. Thermodynamic studies showed that the adsorption process was endothermic and spontaneous. Copyright © 2014. Published by Elsevier B.V.

  9. Optimized Monitoring of Production of Cellulose Nanowhiskers from Opuntia ficus-indica (Nopal Cactus

    Directory of Open Access Journals (Sweden)

    Horacio Vieyra

    2015-01-01

    Full Text Available Preparation of cellulose nanowhiskers (CNWs has grown significantly because they are useful for a wide range of applications. Additional advantage in their design requires that they meet the following characteristics: nontoxicity, abundance, sustainability, renewability, and low cost. To address these requirements, nanowhiskers were prepared from Opuntia ficus-indica (nopal cellulose by acid hydrolysis. Monitoring the process of CNWs preparation is necessary to ensure maximum yield and purity of the end product. In this study, the cellulose preparation was monitored by analyzing microscopic morphology by SEM; the purity degree was determined by fluorescence microscopy as a novel and rapid technique, and FTIR spectroscopy was used for confirmation. The additional parameters that monitored the process were the crystallinity index by X-ray diffraction and the size of the particle by dynamic light scattering (DLS. Nopal cellulose was found to be comparable to commercial microcrystalline cellulose. The use of Opuntia ficus-indica is a viable alternative for the production of highly pure CNWs and the strategy to supervise the preparation process was rapid.

  10. Prevalence and trends of cellulosics in pharmaceutical dosage forms.

    Science.gov (United States)

    Mastropietro, David J; Omidian, Hossein

    2013-02-01

    Many studies have shown that cellulose derivatives (cellulosics) can provide various benefits when used in virtually all types of dosage forms. Nevertheless, the popularity of their use in approved drug products is rather unknown. This research reports the current prevalence and trends of use for 15 common cellulosics in prescription drug products. The cellulosics were powdered and microcrystalline cellulose (MCC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), hypromellose (HPMC), HPMC phthalate, HPMC acetate succinate, cellulose acetate (CA), CA phthalate, sodium (Na) and calcium (Ca) carboxymethylcellulose (CMC), croscarmellose sodium (XCMCNa), methyl cellulose, and low substituted HPC. The number of brand drug products utilizing each cellulosics was determined using the online drug index Rxlist. A total of 607 brand products were identified having one or more of the cellulosics as an active or inactive ingredient. An array of various dosage forms was identified and revealed HPMC and MCC to be the most utilized cellulosics in all products followed by XCMCNa and HPC. Many products contained two or more cellulosics in the formulation (42% containing two, 23% containing three, and 4% containing 4-5). The largest combination occurrence was HPMC with MCC. The use of certain cellulosics within different dosage form types was found to contain specific trends. All injectables utilized only CMCNa, and the same with all ophthalmic solutions utilizing HPMC, and otic suspensions utilizing HEC. Popularity and trends regarding cellulosics use may occur based on many factors including functionality, safety, availability, stability, and ease of manufacturing.

  11. Model films of cellulose. I. Method development and initial results

    NARCIS (Netherlands)

    Gunnars, S.; Wågberg, L.; Cohen Stuart, M.A.

    2002-01-01

    This report presents a new method for the preparation of thin cellulose films. NMMO (N- methylmorpholine- N-oxide) was used to dissolve cellulose and addition of DMSO (dimethyl sulfoxide) was used to control viscosity of the cellulose solution. A thin layer of the cellulose solution is spin- coated

  12. Cellulosic ethanol: status and innovation

    Energy Technology Data Exchange (ETDEWEB)

    Lynd, Lee R.; Liang, Xiaoyu; Biddy, Mary J.; Allee, Andrew; Cai, Hao; Foust, Thomas; Himmel, Michael E.; Laser, Mark S.; Wang, Michael; Wyman, Charles E.

    2017-06-01

    Although the purchase price of cellulosic feedstocks is competitive with petroleum on an energy basis, the cost of lignocellulose conversion to ethanol using today’s technology is high. Cost reductions can be pursued via either in-paradigm or new-paradigm innovation. As an example of new-paradigm innovation, consolidated bioprocessing using thermophilic bacteria combined with milling during fermentation (cotreatment) is analyzed. Acknowledging the nascent state of this approach, our analysis indicates potential for radically improved cost competitiveness and feasibility at smaller scale compared to current technology, arising from (a) R&D-driven advances (consolidated bioprocessing with cotreatment in lieu of thermochemical pretreatment and added fungal cellulase), and (b) configurational changes (fuel pellet coproduction instead of electricity, gas boiler(s) in lieu of a solid fuel boiler).

  13. Preparation of membranes from cellulose obtained of sugarcane bagasse

    International Nuclear Information System (INIS)

    Pereira, Paulo Henrique Fernandes; Cioffi, Maria Odila Hilario; Voorwald, Herman Jacobus Cornelis; Pinho, Maria Noberta de; Silva, Maria Lucia Caetano Pinto da

    2010-01-01

    In this work, cellulose obtained from sugarcane bagasse to produce both cellulose and acetylated cellulose to prepare asymmetric membranes. Membranes was procedure used a mixture of materials of DMAc/ LiCl systemic in different conditions. Cellulose and acetylated cellulose were characterized by thermogravimetric (TG), Xray diffraction (XRD) and scanning Electron Microscopy (SEM). Observed less stability thermal of acetylated cellulose when compared of cellulose. All membranes procedure were asymmetric, characterized by presence of a dense skin and porous support can be observed. SEM showed that the morphology of the superficial of membranes depends on the method preparation. (author)

  14. Utilization of cellulosic waste for energy production

    Science.gov (United States)

    Deshpande, V.; Mishra, C.; Rao, M.; Seeta, R.; Srinivasan, M. C.; Jagannathan, V.

    1980-01-01

    Bioconversion of cellulose for the production of food or alcohol is of importance for the utilization of a renewable and abundant resource. The hydrolysis of different cellulosic materials by the cellulolytic enzymes produced by Penicillium funiculosum was studied. Fifty to 70% saccharification was obtained from pretreated bagasse, cotton and wood. The effect of different pretreatments to make the cellulose more susceptible to enzyme breakdown was also studied. Alkali pretreatment was found to be effective for most of the substrates. The production of alcohol from the hydrolysates by yeast fermentation without isolation of glucose was studied.

  15. Preparation of biocompatible magnetite-carboxymethyl cellulose nanocomposite: characterization of nanocomposite by FTIR, XRD, FESEM and TEM.

    Science.gov (United States)

    Habibi, Neda

    2014-10-15

    The preparation and characterization of magnetite-carboxymethyl cellulose nano-composite (M-CMC) material is described. Magnetite nano-particles were synthesized by a modified co-precipitation method using ferrous chloride tetrahydrate and ferric chloride hexahydrate in ammonium hydroxide solution. The M-CMC nano-composite particles were synthesized by embedding the magnetite nanoparticles inside carboxymethyl cellulose (CMC) using a freshly prepared mixture of Fe3O4 with CMC precursor. Morphology, particle size, and structural properties of magnetite-carboxymethyl cellulose nano-composite was accomplished using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transformed infrared (FTIR) and field emission scanning electron microscopy (FESEM) analysis. As a result, magnetite nano-particles with an average size of 35nm were obtained. The biocompatible Fe3O4-carboxymethyl cellulose nano-composite particles obtained from the natural CMC polymers have a potential range of application in biomedical field. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Homogeneous preparation of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from sugarcane bagasse cellulose in ionic liquid.

    Science.gov (United States)

    Huang, Kelin; Wang, Ben; Cao, Yan; Li, Huiquan; Wang, Jinshu; Lin, Weijiang; Mu, Chaoshi; Liao, Dankui

    2011-05-25

    Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The (13)C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth.

  17. Supercritical antisolvent co-precipitation of rifampicin and ethyl cellulose.

    Science.gov (United States)

    Djerafi, Rania; Swanepoel, Andri; Crampon, Christelle; Kalombo, Lonji; Labuschagne, Philip; Badens, Elisabeth; Masmoudi, Yasmine

    2017-05-01

    Rifampicin-loaded submicron-sized particles were prepared through supercritical anti-solvent process using ethyl cellulose as polymeric encapsulating excipient. Ethyl acetate and a mixture of ethyl acetate/dimethyl sulfoxide (70/30 and 85/15) were used as solvents for both drug and polymeric excipient. When ethyl acetate was used, rifampicin was crystallized separately without being embedded within the ethyl cellulose matrix while by using the ethyl acetate/dimethyl sulfoxide mixture, reduced crystallinity of the active ingredient was observed and a simultaneous precipitation of ethyl cellulose and drug was achieved. The effect of solvent/CO 2 molar ratio and polymer/drug mass ratio on the co-precipitates morphology and drug loading was investigated. Using the solvent mixture, co-precipitates with particle sizes ranging between 190 and 230nm were obtained with drug loading and drug precipitation yield from respectively 8.5 to 38.5 and 42.4 to 77.2% when decreasing the ethyl cellulose/rifampicin ratio. Results show that the solvent nature and the initial drug concentrations affect morphology and drug precipitation yield of the formulations. In vitro dissolution studies revealed that the release profile of rifampicin was sustained when co-precipitation was carried out with the solvent mixture. It was demonstrated that the drug to polymer ratio influenced amorphous content of the SAS co-precipitates. Differential scanning calorimetry thermograms and infrared spectra revealed that there is neither interaction between rifampicin and the polymer nor degradation of rifampicin during co-precipitation. In addition, stability stress tests on SAS co-precipitates were carried out at 75% relative humidity and room temperature in order to evaluate their physical stability. SAS co-precipitates were X-ray amorphous and remained stable after 6months of storage. The SAS co-precipitation process using a mixture of ethyl acetate/dimethyl sulfoxide demonstrates that this strategy can

  18. Strong and Optically Transparent Films Prepared Using Cellulosic Solid Residue Recovered from Cellulose Nanocrystals Production Waste Stream

    Science.gov (United States)

    Qianqian Wang; J.Y. Zhu; John M. Considine

    2013-01-01

    We used a new cellulosic material, cellulosic solid residue (CSR), to produce cellulose nanofibrils (CNF) for potential high value applications. Cellulose nanofibrils (CNF) were produced from CSR recovered from the hydrolysates (waste stream) of acid hydrolysis of a bleached Eucalyptus kraft pulp (BEP) to produce nanocrystals (CNC). Acid hydrolysis greatly facilitated...

  19. Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

    Directory of Open Access Journals (Sweden)

    Lifeng Liu

    Full Text Available Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1, a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

  20. Regenerated cellulose from high alpha cellulose pulp of steam-exploded sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Natthapong Phinichka

    2018-01-01

    Full Text Available The need for biodegradable films for packaging, absorbents, and fibers has encouraged the development of novel biodegradable films made from natural sources, especially agricultural byproducts. The present investigation involved preparation of alpha cellulose and regenerated cellulose film, in view of the use of sugarcane bagasse, the cellulose-rich waste from the sugar industry. In order to prepare a cellulose pulp, the bagasse was exploded separately by saturated steam at temperatures of 195 °C and 205 °C for 5 min, washed, oven-dried, and submitted to an alkali pulping and bleaching process. The chemical compositions consisted of alpha cellulose, holocellulose, lignin, and the extractives of the bagasse and its pulp were analyzed. The results showed that the pulp contained high levels of alpha cellulose and low lignin. The cellulose pulp was being successfully regenerated as cellulosic films in an acid coagulation bath at different coagulation times. The characteristics of the steam exploded bagasse, cellulose pulp, and regenerated cellulose were investigated by SEM, XRD, FITR, TGA, tensile test, contact angle, and water retention measurement. The results of the XRD, FTIR and TGA all indicated that high alpha cellulose with low lignin pulp could successfully be made from steam-exploded sugarcane bagasse. The SEM images, contact angles, and water retention values also revealed that the regenerated films coagulated in an acid bath for 15 min were more hydrophilic than those that had coagulated for 30 min. The tensile test indicated that the regenerated cellulose films coagulated for 30 min were stronger than those coagulated for 15 min.

  1. Brittle Culm1, a COBRA-Like Protein, Functions in Cellulose Assembly through Binding Cellulose Microfibrils

    Science.gov (United States)

    Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

    2013-01-01

    Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity. PMID:23990797

  2. Reaction mechanisms in cellulose pyrolysis: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Demmitt, T.F.

    1977-08-01

    A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

  3. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    Science.gov (United States)

    Rapp, F.; Schneider, A.; Elsner, P.

    2014-05-01

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength).

  4. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, F., E-mail: florian.rapp@ict.fraunhofer.de, E-mail: anja.schneider@ict.fraunhofer.de; Schneider, A., E-mail: florian.rapp@ict.fraunhofer.de, E-mail: anja.schneider@ict.fraunhofer.de [Fraunhofer Institute for Chemical Technology ICT (Germany); Elsner, P., E-mail: peter.elsner@ict.fraunhofer.de [Fraunhofer Institute for Chemical Technology ICT, Germany and Karlsruhe Institute of Technology KIT (Germany)

    2014-05-15

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO{sub 2} balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

  5. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    International Nuclear Information System (INIS)

    Rapp, F.; Schneider, A.; Elsner, P.

    2014-01-01

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO 2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

  6. Cellulose based cationic adsorbent fabricated via radiation grafting process for treatment of dyes waste water.

    Science.gov (United States)

    Goel, Narender Kumar; Kumar, Virendra; Misra, Nilanjal; Varshney, Lalit

    2015-11-05

    A cationized adsorbent was prepared from cellulosic cotton fabric waste via a single step-green-radiation grafting process using gamma radiation source, wherein poly[2-(methacryloyloxy) ethyl]trimethylammonium chloride (PMAETC) was covalently attached to cotton cellulose substrate. Radiation grafted (PMAETC-g-cellulose) adsorbent was investigated for removal of acid dyes from aqueous solutions using two model dyes: Acid Blue 25 (AB25) and Acid Blue 74 (AB74). The equilibrium adsorption data was analyzed by Langmuir and Freundlich isotherms, whereas kinetic data was analyzed by pseudo first order, pseudo second order, intra particle diffusion and Boyd's models. The PMAETC-g-cellulose adsorbent with 25% grafting yield exhibited equilibrium adsorption capacities of ∼ 540.0mg/g and ∼ 340.0mg/g for AB25 and AB74, respectively. Linear and nonlinear fitting of adsorption data suggested that the equilibrium adsorption process followed Langmuir adsorption isotherm model, whereas, the kinetic adsorption process followed pseudo-second order model. The multi-linearities observed in the intra-particle kinetic plots suggested that the intraparticle diffusion was not the only rate-controlling process in the adsorption of acid dyes on the adsorbent, which was further supported by Boyd's model. The adsorbent could be regenerated by eluting the adsorbed dye from the adsorbent and could be repeatedly used. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. The Effect of Mechanochemical Treatment of the Cellulose on Characteristics of Nanocellulose Films

    Science.gov (United States)

    Barbash, V. A.; Yaschenko, O. V.; Alushkin, S. V.; Kondratyuk, A. S.; Posudievsky, O. Y.; Koshechko, V. G.

    2016-09-01

    The development of the nanomaterials with the advanced functional characteristics is a challenging task because of the growing demand in the market of the optoelectronic devices, biodegradable plastics, and materials for energy saving and energy storage. Nanocellulose is comprised of the nanosized cellulose particles, properties of which depend on characteristics of plant raw materials as well as methods of nanocellulose preparation. In this study, the effect of the mechanochemical treatment of bleached softwood sulfate pulp on the optical and mechanical properties of nanocellulose films was assessed. It was established that the method of the subsequent grinding, acid hydrolysis and ultrasound treatment of cellulose generated films with the significant transparency in the visible spectral range (up to 78 % at 600 nm), high Young's modulus (up to 8.8 GPa), and tensile strength (up to 88 MPa) with increased ordering of the packing of the cellulose macromolecules. Morphological characterization was done using the dynamic light scattering (DLS) analyzer and transmission electron microscopy (TEM). The nanocellulose particles had an average diameter of 15-30 nm and a high aspect ratio in the range 120-150. The crystallinity was increased with successive treatments as shown by the X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. The thermal degradation behavior of cellulose samples was explored by thermal gravimetric analysis (TGA).

  8. Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

    Directory of Open Access Journals (Sweden)

    Anand Kumar Veeramachineni

    2016-06-01

    Full Text Available Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA, Infrared Spectroscopy (FTIR, X-Ray Diffraction (XRD, Differential Scanning Calorimetry (DSC and Field Emission Scanning Electronic Microscopy (FESEM. The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

  9. Bioplastic production from cellulose of oil palm empty fruit bunch

    Science.gov (United States)

    Isroi; Cifriadi, A.; Panji, T.; Wibowo, Nendyo A.; Syamsu, K.

    2017-05-01

    Empty fruit bunch is available abundantly in Indonesia as side product of CPO production. EFB production in Indonesia reached 28.65 million tons in 2015. EFB consist of 36.67% cellulose, 13.50% hemicellulose and 31.16% lignin. By calculation, potential cellulose from EFB is 11.50 million tons. Cellulose could be utilized as source for bioplastic production. This research aims to develop bioplastic production based on cellulose from EFB and to increase added value of EFB. Cellulose fiber has no plastic properties. Molecular modification of cellulose, composite with plasticizer and compatibilizer is a key success for utilization of cellulose for bioplastic. Main steps of bioplastic production from EFB are: 1) isolation and purification of cellulose, 2) cellulose modification and 3) synthesis of bioplastic. Cellulose was isolated by sodium hydroxide methods and bleached using sodium hypochlorite. Purity of obtained cellulose was 97%. Cellulose yield could reach 30% depend on cellulose content of EFB. Cellulose side chain was oxidized to reduce hydroxyl group and increase the carboxyl group. Bioplastic synthesis used glycerol as plasticizer and cassava starch as matrix. This research was successfully producing bioplastic sheet by casting method. In future prospects, bioplastic from EFB cellulose can be developed as plastic bag and food packaging.

  10. Efficient cellulose solvent: quaternary ammonium chlorides.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; El Seoud, Omar A; Heinze, Thomas

    2013-10-01

    Pure quaternary tetraalkylammonium chlorides with one long alkyl chain dissolved in various organic solvents constitute a new class of cellulose solvents. The electrolytes are prepared in high yields and purity by Menshutkin quaternization, an inexpensive and easy synthesis route. The pure molten tetraalkylammonium chlorides dissolve up to 15 wt% of cellulose. Cosolvents, including N,N-dimethylacetamide (DMA), may be added in large excess, leading to a system of decreased viscosity. Contrary to the well-established solvent DMA/LiCl, cellulose dissolves in DMA/quaternary ammonium chlorides without any pretreatment. Thus, the use of the new solvent avoids some disadvantages of DMA/LiCl and ionic liquids, the most extensively employed solvents for homogeneous cellulose chemistry. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Cellulose and hemicelluloses recovery from grape stalks.

    Science.gov (United States)

    Spigno, Giorgia; Pizzorno, Tiziana; De Faveri, Dante Marco

    2008-07-01

    In this work, two mild chemical fractionation procedures were compared to separate and recover lignocellulosic components from grape stalks. The first method consisted of mild acid hydrolysis for hemicelluloses separation, followed by an alkaline/oxidative step for lignin solubilization, while in the second method the acid hydrolysis was preceded by an alkali steeping phase. Influence of the length of the first step of both methods (from 2 to 24 h) on monosaccharides and cellulose yields was investigated. The first method allowed a higher sugar recovery for longer times, and a slightly lower amount of cellulose. Cellulose residues from both the methods were comparable for cellulose content and thermal profile (studied by differential scanning calorimetry). Acid hydrolysis of the first step was carried out also in autoclave, showing that xylan degradation could be described by a first order kinetics where at higher temperature the presence of a fast reaction and a slow reacting fraction must be accounted for.

  12. Cellulose whiskers: preparation, characterization and surface modification

    International Nuclear Information System (INIS)

    Taipina, Marcia O.; Ferrarezi, Marcia M.F.; Goncalves, Maria C.

    2011-01-01

    The main objectives of this work were to produce cellulose whiskers (from cotton fibers) by acid hydrolysis and subsequently modify the surface of these whiskers with 3-iso-cyanate-propyltrietoxy-silane. Cellulose whiskers structures were characterized by X-ray diffraction and Fourier transform infrared and their morphologies were investigated by scanning and transmission electron microscopy. Due to the hydrophilic nature of native cellulose, the formation of cellulose whisker nanocomposites is limited to water-soluble polymers. The applied methodology for surface modification of the whiskers allowed to obtain nanofibers with surface features more appropriate to allow the adhesion at fiber-matrix interface, which may result in a better performance of these fibers as reinforcing agents of hydrophobic polymer matrices. (author)

  13. Characterization of TEMPO-oxidized bacterial cellulose

    International Nuclear Information System (INIS)

    Nascimento, Eligenes S.; Pereira, Andre L.S.; Lima, Helder L.; Barroso, Maria K. de A.; Barros, Matheus de O.; Morais, Joao P.S.; Borges, Maria de F.; Rosa, Morsyleide de F.

    2015-01-01

    The aim of this study was to characterize the TEMPO-oxidized bacterial cellulose, as a preliminary research for further application in nanocomposites. Bacterial cellulose (BC) was selectively oxidized at C-6 carbon by TEMPO radical. Oxidized bacterial cellulose (BCOX) was characterized by TGA, FTIR, XRD, and zeta potential. BCOX suspension was stable at pH 7.0, presented a crystallinity index of 83%, in spite of 92% of BC, because of decrease in the free hydroxyl number. FTIR spectra showed characteristic BC bands and, in addition, band of carboxylic group, proving the oxidation. BCOX DTG showed, in addition to characteristic BC thermal events, a maximum degradation peak at 233 °C, related to sodium anhydro-glucuronate groups formed during the cellulose oxidation. Thus, BC can be TEMPO-oxidized without great loss in its structure and properties. (author)

  14. Cellulosic ethanol is ready to go

    Energy Technology Data Exchange (ETDEWEB)

    Burke, M. [SunOpta BioProcess Group, Brampton, ON (Canada)

    2006-07-01

    A corporate overview of the SunOpta organization was presented. The organization includes three divisions, notably organic food, industrial minerals, and a bioprocess group. It is a Canadian organization that has experienced over 60 per cent growth per year since 1999. The presentation provided a history of the bioprocess group from 1973 to 2003. The presentation also illustrated the biomass process from wood, straw or corn stover to cellulosic ethanol and acetone and butanol. Several images were presented. The production of xylitol from oat hulls and birch and from ryegrass straw to linerboard was also illustrated. Last, the presentation illustrated the biomass production of cellulose, hemicellulose and lignin extraction as well as the ammonia pretreatment of cellulosics. The presentation also listed several current and future developments such as an expansion plan and implementation of cellulosic ethanol. Economic success was defined as requiring proximity to market; high percentage concentration to distillation; and co-located within existing infrastructure. figs.

  15. Cellulose: To depolymerize… or not to?

    Science.gov (United States)

    Coseri, Sergiu

    Oxidation of the primary OH groups in cellulose is a pivotal reaction both at lab and industrial scale, leading to the value-added products, i.e. oxidized cellulose which have tremendous applications in medicine, pharmacy and hi-tech industry. Moreover, the introduction of carboxyl moieties creates prerequisites for further cellulose functionalization through covalent attachment or electrostatic interactions, being an essential achievement designed to boost the area of cellulose-based nanomaterials fabrication. Various methods for the cellulose oxidation have been developed in the course of time, aiming the selective conversion of the OH groups. These methods use: nitrogen dioxide in chloroform, alkali metal nitrites and nitrates, strong acids alone or in combination with permanganates or sodium nitrite, ozone, and sodium periodate or lead (IV) tetraacetate. In the case of the last two reagents, cellulose dialdehydes derivatives are formed, which are further oxidized by sodium chlorite or hydrogen peroxide to form dicarboxyl groups. A major improvement in the cellulose oxidation was represented by the introduction of the stable nitroxyl radicals, such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). However, a major impediment for the researchers working in this area is related with the severe depolymerisation occurred during the TEMPO-mediated conversion of CH 2 OH into COOH groups. On the other hand, the cellulose depolymerisation represent the key step, in the general effort of searching for alternative strategies to develop new renewable, carbon-neutral energy sources. In this connection, exploiting the biomass feed stocks to produce biofuel and other low molecular organic compounds, involves a high amount of research to improve the overall reaction conditions, limit the energy consumption, and to use benign reagents. This work is therefore focused on the parallelism between these two apparently antagonist processes involving cellulose, building a necessary

  16. Direct observation of the effects of cellulose synthesis inhibitors using live cell imaging of Cellulose Synthase (CESA) in Physcomitrella patens

    OpenAIRE

    Tran, Mai L.; McCarthy, Thomas W.; Sun, Hao; Wu, Shu-Zon; Norris, Joanna H.; Bezanilla, Magdalena; Vidali, Luis; Anderson, Charles T.; Roberts, Alison W.

    2018-01-01

    Results from live cell imaging of fluorescently tagged Cellulose Synthase (CESA) proteins in Cellulose Synthesis Complexes (CSCs) have enhanced our understanding of cellulose biosynthesis, including the mechanisms of action of cellulose synthesis inhibitors. However, this method has been applied only in Arabidopsis thaliana and Brachypodium distachyon thus far. Results from freeze fracture electron microscopy of protonemal filaments of the moss Funaria hygrometrica indicate that a cellulose s...

  17. Superconducting lead particles produced by chemical techniques

    Science.gov (United States)

    Fariss, T. L.; Nixon, W. E.; Bucelot, T. J.; Deaver, B. S., Jr.; Mitchell, J. W.

    1982-09-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by ˜0.1 K.

  18. Superconducting lead particles produced by chemical techniques

    International Nuclear Information System (INIS)

    Fariss, T.L.; Nixon, W.E.; Bucelot, T.J.; Deaver, B.S. Jr.; Mitchell, J.W.

    1982-01-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by approx.0.1 K

  19. Functional biocompatible magnetite-cellulose nanocomposite fibrous networks: Characterization by fourier transformed infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy analysis.

    Science.gov (United States)

    Habibi, Neda

    2015-02-05

    The preparation and characterization of functional biocompatible magnetite-cellulose nano-composite fibrous material is described. Magnetite-cellulose nano-composite was prepared by a combination of the solution-based formation of magnetic nano-particles and subsequent coating with amino celluloses. Characterization was accomplished using X-ray powder diffraction (XRD), fourier transformed infrared (FTIR) and field emission scanning electron microscopy (FESEM) analysis. The peaks of Fe3O4 in the XRD pattern of nanocomposite confirm existence of the nanoparticles in the amino cellulose matrix. Magnetite-cellulose particles exhibit an average diameter of roughly 33nm as demonstrated by field emission scanning electron microscopy. Magnetite nanoparticles were irregular spheres dispersed in the cellulose matrix. The vibration corresponding to the NCH3 functional group about 2850cm(-1) is assigned in the FTIR spectra. Functionalized magnetite-cellulose nano-composite polymers have a potential range of application as targeted drug delivery system in biomedical field. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Nanofibrillar cellulose films for controlled drug delivery.

    Science.gov (United States)

    Kolakovic, Ruzica; Peltonen, Leena; Laukkanen, Antti; Hirvonen, Jouni; Laaksonen, Timo

    2012-10-01

    Nanofibrillar cellulose (NFC) (also referred to as cellulose nanofibers, nanocellulose, microfibrillated, or nanofibrillated cellulose) has gotten recent and wide attention in various research areas. Here, we report the application of nanofibrillar cellulose as a matrix-former material for long-lasting (up to three months) sustained drug delivery. Film-like matrix systems with drug loadings between 20% and 40% were produced by a filtration method. This simple production method had an entrapment efficacy>90% and offers a possibility for the film thickness adjustment as well as applicability in the incorporation of heat sensitive compounds. The films had excellent mechanical properties suitable for easy handling and shape tailoring of the drug release systems. They were characterized in terms of the internal morphology, and the physical state of the encapsulated drug. The drug release was assessed by dissolution tests, and suitable mathematical models were used to explain the releasing kinetics. The drug release was sustained for a three month period with very close to zero-order kinetics. It is assumed that the nanofibrillar cellulose film sustains the drug release by forming a tight fiber network around the incorporated drug entities. The results indicate that the nanofibrillar cellulose is a highly promising new material for sustained release drug delivery applications. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Mechanical characterization of cellulose single nanofiber by atomic force microscopy

    Science.gov (United States)

    Zhai, Lindong; Kim, Jeong Woong; Lee, Jiyun; Kim, Jaehwan

    2017-04-01

    Cellulose fibers are strong natural fibers and they are renewable, biodegradable and the most abundant biopolymer in the world. So to develop new cellulose fibers based products, the mechanical properties of cellulose nanofibers would be a key. The atomic microscope is used to measure the mechanical properties of cellulose nanofibers based on 3-points bending of cellulose nanofiber. The cellulose nanofibers were generated for an aqueous counter collision system. The cellulose microfibers were nanosized under 200 MPa high pressure. The cellulose nanofiber suspension was diluted with DI water and sprayed on the silicon groove substrate. By performing a nanoscale 3-points bending test using the atomic force microscopy, a known force was applied on the center of the fiber. The elastic modulus of the single nanofiber is obtained by calculating the fiber deflection and several parameters. The elastic modulus values were obtained from different resources of cellulose such as hardwood, softwood and cotton.

  2. Highly porous regenerated cellulose hydrogel and aerogel prepared from hydrothermal synthesized cellulose carbamate

    Science.gov (United States)

    Gan, Sinyee; Chia, Chin Hua; Chen, Ruey Shan; Ellis, Amanda V.; Kaco, Hatika

    2017-01-01

    Here, a stable derivative of cellulose, called cellulose carbamate (CC), was produced from Kenaf (Hibiscus cannabinus) core pulp (KCP) and urea with the aid of a hydrothermal method. Further investigation was carried out for the amount of nitrogen yielded in CC as different urea concentrations were applied to react with cellulose. The effect of nitrogen concentration of CC on its solubility in a urea-alkaline system was also studied. Regenerated cellulose products (hydrogels and aerogels) were fabricated through the rapid dissolution of CC in a urea-alkaline system. The morphology of the regenerated cellulose products was viewed under Field emission scanning electron microscope (FESEM). The transformation of allomorphs in regenerated cellulose products was examined by X-ray diffraction (XRD). The transparency of regenerated cellulose products was determined by Ultraviolet–visible (UV–Vis) spectrophotometer. The degree of swelling (DS) of regenerated cellulose products was also evaluated. This investigation provides a simple and efficient procedure of CC determination which is useful in producing regenerated CC products. PMID:28296977

  3. Effects of Crystal Orientation on Cellulose Nanocrystals−Cellulose Acetate Nanocomposite Fibers Prepared by Dry Spinning

    Science.gov (United States)

    Si Chen; Greg Schueneman; R. Byron Pipes; Jeffrey Youngblood; Robert J. Moon

    2014-01-01

    This work presents the development of dry spun cellulose acetate (CA) fibers using cellulose nanocrystals (CNCs) as reinforcements. Increasing amounts of CNCs were dispersed into CA fibers in efforts to improve the tensile strength and elastic modulus of the fiber. A systematic characterization of dispersion of CNCs in the polymer fiber and their effect on the...

  4. Preparation of cellulose II and IIII films by allomorphic conversion of bacterial cellulose I pellicles

    International Nuclear Information System (INIS)

    Faria-Tischer, Paula C.S.; Tischer, Cesar A.; Heux, Laurent; Le Denmat, Simon; Picart, Catherine; Sierakowski, Maria-R.

    2015-01-01

    The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and III I (Cel III I ) have usually been studied using powder samples from plant or algal cellulose. In this work, the conversion of Cel I into Cel II and Cel III I was performed on bacterial cellulose films without any mechanical disruption. The surface texture of the films was observed by atomic force microscopy (AFM) and the morphology of the constituting cellulose ribbons, by transmission electron microscopy (TEM). The structural changes were characterized using solid-state NMR spectroscopy as well as X-ray and electron diffraction. The allomorphic change into Cel II and Cel III I resulted in films with different crystallinity, roughness and hydrophobic/hydrophilicity surface and the films remained intact during all process of allomorphic conversion. - Highlights: • Description of a method to modify the allomorphic structure of bacterial cellulose films • Preparation of films with specific morphologies and hydrophobic/hydrophilic surface characters • First report on cellulose III films from bacterial cellulose under swelling conditions • Detailed characterization of cellulose II and III films with complementary techniques • Development of films with specific properties as potential support for cells, enzymes, and drugs

  5. Properties of cellulose derivatives produced from radiation-Modified cellulose pulps

    International Nuclear Information System (INIS)

    Iller, Edward; Stupinska, Halina; Starostka, Pawel

    2007-01-01

    The aim of project was elaboration of radiation methods for properties modification of cellulose pulps using for derivatives production. The selected cellulose pulps were exposed to an electron beam with energy 10 MeV in a linear accelerator. After irradiation pulps underwent the structural and physico-chemical investigations. The laboratory test for manufacturing carboxymethylocellulose (CMC), cellulose carbamate (CC) and cellulose acetate (CA) with cellulose pulps irradiated dose 10 and 15 kGy have been performed. Irradiation of the pulp influenced its depolimerisation degree and resulted in the drop of viscosity of CMC. However, the expected level of cellulose activation expressed as a rise of the substitution degree or increase of the active substance content in the CMC sodium salt was not observed. In the case of cellulose esters (CC, CA) formation, the action of ionising radiation on cellulose pulps with the dose 10 and 15 kGy enables obtaiment of the average values of polimerisation degree as required for CC soluble in aqueous sodium hydroxide solution. The properties of derivatives prepared by means of radiation and classic methods were compared

  6. Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

    International Nuclear Information System (INIS)

    Namsaraev, B.B.; Kuznetsova, E.A.; Termkhitarova, N.G.

    1987-01-01

    Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co 60 ) has been carried out using the RKh-30 device with 35.9 Gy/min dose rate. Radiation monitoring has been carried out by the standard ferrosulfate method. Samples have been irradiated in dry state or when water presenting with MGy. It is detected that the accumulating culture with the growth on the irradiated cellulose has a lag-phase, which duration reduces when the cellulose cleaning by flushing with distillation water. The culture has higher growth and substrate consumption rate when growing by cellulose irradiated in comparison with non-irradiated one. The economical coefficient is the same in using both the irradiated and non-irradiated cellulose. The quantity of forming reducing saccharides, organic acids, methane and carbon dioxide is the same both when cultivating by irradiated cellulose and by non-irradiated. pH of the culture liquid is shifted to the acid nature in the process of growth

  7. Cellulose nanofibers from Curaua fibers

    International Nuclear Information System (INIS)

    Correa, Ana Carolina; Pessan, Luiz A.; Teixeira, Eliangela M.; Marconcini, Jose M.; Mattoso, Luiz H.C.

    2009-01-01

    Curaua is a plant from Amazon region whose leaves were used by the indians of the region to make nets, ropes, fishing wires, etc., due to their high mechanical resistance. Nowadays, some industries, mainly textile and automobile, have increased their interest on these fibers to prepare polymer composites, because their properties could be compared to composites with glass fibers. In this work, cellulose nanofibers were obtained from curaua fibers, which were submitted to alkaline treatment with a solution of NaOH 5%. Nanofibers, in watery suspension, were characterized morphologically by TEM and AFM, and they show needle like format and the ratio L/D of 14. The suspension was dried by freeze dried process, in vacuum and air circulation oven, and these nanofibers were analyzed by x-ray diffraction, presenting high crystalline index, and by thermogravimetric analysis (TGA), which showed that nanofibers have poorer thermal stability than the treated fiber, but they can reach values next to the ones of the original fibers, depending on the drying process of the suspension. (author)

  8. Microwave-Assisted Hydrothermal Synthesis of Cellulose/Hydroxyapatite Nanocomposites

    Directory of Open Access Journals (Sweden)

    Lian-Hua Fu

    2016-09-01

    Full Text Available In this paper, we report a facile, rapid, and green strategy for the synthesis of cellulose/hydroxyapatite (HA nanocomposites using an inorganic phosphorus source (sodium dihydrogen phosphate dihydrate (NaH2PO4·2H2O, or organic phosphorus sources (adenosine 5′-triphosphate disodium salt (ATP, creatine phosphate disodium salt tetrahydrate (CP, or D-fructose 1,6-bisphosphate trisodium salt octahydrate (FBP through the microwave-assisted hydrothermal method. The effects of the phosphorus sources, heating time, and heating temperature on the phase, size, and morphology of the products were systematically investigated. The experimental results revealed that the phosphate sources played a critical role on the phase, size, and morphology of the minerals in the nanocomposites. For example, the pure HA was obtained by using NaH2PO4·2H2O as phosphorus source, while all the ATP, CP, and FBP led to the byproduct, calcite. The HA nanostructures with various morphologies (including nanorods, pseudo-cubic, pseudo-spherical, and nano-spherical particles were obtained by varying the phosphorus sources or adjusting the reaction parameters. In addition, this strategy is surfactant-free, avoiding the post-treatment procedure and cost for the surfactant removal from the product. We believe that this work can be a guidance for the green synthesis of cellulose/HA nanocomposites in the future.

  9. Antifouling Cellulose Hybrid Biomembrane for Effective Oil/Water Separation.

    Science.gov (United States)

    Kollarigowda, Ravichandran H; Abraham, Sinoj; Montemagno, Carlo D

    2017-09-06

    Oil/water separation has been of great interest worldwide because of the increasingly serious environmental pollution caused by the abundant discharge of industrial wastewater, oil spill accidents, and odors. Here, we describe simple and economical superhydrophobic hybrid membranes for effective oil/water separation. Eco-friendly, antifouling membranes were fabricated for oil/water separation, waste particle filtration, the blocking of thiol-based odor materials, etc., by using a cellulose membrane (CM) filter. The CM was modified from its original superhydrophilic nature into a superhydrophobic surface via a reversible addition-fragmentation chain transfer technique. The block copolymer poly{[3-(trimethoxysilyl)propyl acrylate]-block-myrcene} was synthesized using a "grafting-from" approach on the CM. The surface contact angle that we obtained was >160°, and absorption tests of several organic contaminants (oils and solvents) exhibited superior levels of extractive activity and excellent reusability. These properties rendered this membrane a promising surface for oil/water separation. Interestingly, myrcene blocks thiol (through "-ene-" chemistry) contaminants, thereby bestowing a pleasant odor to polluted water by acting as an antifouling material. We exploited the structural properties of cellulose networks and simple chemical manipulations to fabricate an original material that proved to be effective in separating water from organic and nano/microparticulate contaminants. These characteristics allowed our material to effectively separate water from oily/particulate phases as well as embed antifouling materials for water purification, thus making it an appropriate absorber for chemical processes and environmental protection.

  10. Self-assembly and alignment of semiconductor nanoparticles on cellulose nanocrystals

    OpenAIRE

    Padalkar, Sonal; Capadona, Jeff R.; Rowan, Stuart J.; Weder, Christoph; Moon, Robert J.; Stanciu, Lia A.

    2011-01-01

    The synthesis of cadmium sulfide (CdS), zinc sulfide (ZnS), and lead sulfide (PbS) nanoparticle chains on cellulose nanocrystal (CNC) templates can be accomplished by the reaction of the precursor salts. The use of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), was critical for the synthesis of well-defined semiconductor nanoparticle chains on the surface of the CNCs. The semiconductor nanoparticle particle size and packing density on CNC surface could be controlled by the vari...

  11. Steric Stabilization of “Charge-Free” Cellulose Nanowhiskers by Grafting of Poly(ethylene glycol)

    OpenAIRE

    Araki, Jun; Mishima, Shiho

    2014-01-01

    A sterically stabilized aqueous suspension of “charge-free” cellulose nanowhiskers was prepared by hydrochloric acid hydrolysis of cotton powders and subsequent surface grafting of monomethoxy poly(ethylene glycol) (mPEG). The preparation scheme included carboxylation of the terminal hydroxyl groups in mPEG via oxidation with silica gel particles carrying 2,2,6,6-tetramethyl-1-pyperidinyloxyl (TEMPO) moieties and subsequent esterification between terminal carboxyls in mPEG and surface hydroxy...

  12. The Effect of Mechanochemical Treatment of the Cellulose on Characteristics of Nanocellulose Films

    OpenAIRE

    Barbash, V. A.; Yaschenko, O. V.; Alushkin, S. V.; Kondratyuk, A. S.; Posudievsky, O. Y.; Koshechko, V. G.

    2016-01-01

    The development of the nanomaterials with the advanced functional characteristics is a challenging task because of the growing demand in the market of the optoelectronic devices, biodegradable plastics, and materials for energy saving and energy storage. Nanocellulose is comprised of the nanosized cellulose particles, properties of which depend on characteristics of plant raw materials as well as methods of nanocellulose preparation. In this study, the effect of the mechanochemical treatment ...

  13. Cellulose Anionic Hydrogels Based on Cellulose Nanofibers As Natural Stimulants for Seed Germination and Seedling Growth.

    Science.gov (United States)

    Zhang, Hao; Yang, Minmin; Luan, Qian; Tang, Hu; Huang, Fenghong; Xiang, Xia; Yang, Chen; Bao, Yuping

    2017-05-17

    Cellulose anionic hydrogels were successfully prepared by dissolving TEMPO-oxidized cellulose nanofibers in NaOH/urea aqueous solution and being cross-linked with epichlorohydrin. The hydrogels exhibited microporous structure and high hydrophilicity, which contribute to the excellent water absorption property. The growth indexes, including the germination rate, root length, shoot length, fresh weight, and dry weight of the seedlings, were investigated. The results showed that cellulose anionic hydrogels with suitable carboxylate contents as plant growth regulators could be beneficial for seed germination and growth. Moreover, they presented preferable antifungal activity during the breeding and growth of the sesame seed breeding. Thus, the cellulose anionic hydrogels with suitable carboxylate contents could be applied as soilless culture mediums for plant growth. This research provided a simple and effective method for the fabrication of cellulose anionic hydrogel and evaluated its application in agriculture.

  14. Particle Dynamics in the Sea: Processes of Production and Loss Governing the Abundance of Marine Snow

    Science.gov (United States)

    1990-01-05

    matter within aggregates. calculated area of a circle having a diameter By comparison, the density of dry cellulose equal to the maximum cross-sectional di...Diatom floc samples for nutrient analysis contained eight aggregates each. Samples were filtered through clean, sterile 0.2 pm cellulose membrane...concsentiations. Particles formed by bacterial aggregation are held together by web-like structures of microfibrils produced I., the bacteri- on the particles

  15. Production of Cellulosic Polymers from Agricultural Wastes

    Directory of Open Access Journals (Sweden)

    A. U. Israel

    2008-01-01

    Full Text Available Cellulosic polymers namely cellulose, di-and triacetate were produced from fourteen agricultural wastes; Branch and fiber after oil extraction from oil palm (Elais guineensis, raffia, piassava, bamboo pulp, bamboo bark from raphia palm (Raphia hookeri, stem and cob of maize plant (Zea mays, fruit fiber from coconut fruit (Cocos nucifera, sawdusts from cotton tree (Cossypium hirsutum, pear wood (Manilkara obovata, stem of Southern gamba green (Andropogon tectorus, sugarcane baggase (Saccharium officinarum and plantain stem (Musa paradisiaca. They were subjected to soda pulping and hypochlorite bleaching system. Results obtained show that pulp yield from these materials were: 70.00, 39.59, 55.40, 86.00, 84.60, 80.00, 40.84, 81.67, 35.70, 69.11, 4.54, 47.19, 31.70 and 52.44% respectively. The pulps were acetylated with acetic anhydride in ethanoic acid catalyzed by conc. H2SO4 to obtain cellulose derivatives (Cellulose diacetate and triacetate. The cellulose diacetate yields were 41.20, 17.85, 23.13, 20.80, 20.23, 20.00, 39.00, 44.00, 18.80, 20.75, 20.03, 41.20, 44.00, and 39.00% respectively while the results obtained as average of four determinations for cellulose triacetate yields were: 52.00, 51.00, 43.10, 46.60, 49.00, 35.00, 40.60, 54.00, 57.50, 62.52, 35.70. 52.00, 53.00 and 38.70% respectively for all the agricultural wastes utilized. The presence of these cellulose derivatives was confirmed by a solubility test in acetone and chloroform.

  16. Effect of ionizing radiation on starch and cellulose

    International Nuclear Information System (INIS)

    Klenha, J.; Bockova, J.

    1973-09-01

    The investigation is reported of the effects of ionizing radiation both on macromolecular systems generally and on polysaccharides, starch and cellulose. Attention is focused on changes in the physical and physico-chemical properties of starch and cellulose, such as starch swelling, gelation, viscosity, solubility, reaction with iodine, UV, IR and ESR spectra, chemical changes resulting from radiolysis and from the effect of amylases on irradiated starch, changes in cellulose fibre strength, water absorption, stain affinity, and also the degradation of cellulose by radiation and the effect of cellulases on irradiated cellulose. Practical applications of the findings concerning cellulose degradation are discussed. (author)

  17. Experimental study on the liquefaction of cellulose in supercritical ethanol

    Science.gov (United States)

    Peng, Jinxing; Liu, Xinyuan; Bao, Zhenbo

    2018-03-01

    Cellulose is the major composition of solid waste for producing biofuel; cellulose liquefaction is helpful for realizing biomass supercritical liquefaction process. This paper is taking supercritical ethanol as the medium, liquefied cellulose with the intermittence installation of high press cauldron. Experiments have studied technical condition and the technology parameter of cellulose liquefaction in supercritical ethanol, and the pyrolysis mechanism was analysed based on the pyrolysis product. Results show that cellulose can be liquefied, can get good effect through appropriate technology condition. Under not catalyst, highest liquefaction rate of cellulose can reach 73.5%. The composition of the pyrolysis product was determined by GC-MS.

  18. Electrically conductive bacterial cellulose composite membranes produced by the incorporation of graphite nanoplatelets in pristine bacterial cellulose membranes

    Directory of Open Access Journals (Sweden)

    T. Zhou

    2013-09-01

    Full Text Available Graphite nanoplatelets (GNPs were utilized to improve the electrical conductivity of pristine bacterial cellulose (BC membranes. By physical and chemical methods, flake-shaped GNPs, weaving through the surface layer of web-like cellulose nanofibrils, were indeed fixed or trapped by the adjacent nanofibrils in the BC surface network, for comparison, rod-shaped multi-walled carbon nanotubes (MWCNTs were homogeneously inserted into BC membrane through the pore structures and tunnels within the BC membrane. Strong physical and chemical interaction exists between the BC nanofibrils and the particles of GNP or MWCNT even after 15 h sonication. BC membrane with 8.7 wt% incorporated GNPs reached the maximum electrical conductivity of 4.5 S/cm, while 13.9 wt% MWCNT/BC composite membrane achieved the maximum electrical conductivity of 1.2 S/cm. Compared with one dimensional (1-D MWCNTs, as long as GNPs inserted into BC membranes, the 2-D reinforcement of GNPs was proven to be more effective in improving the electrical conductivity of BC membranes thus not only break the bottleneck of further improvement of the electrical conductivity of BC-based composite membranes but also broaden the applications of BC and GNPs.

  19. Preparation of Esterified Bacterial Cellulose for Improved Mechanical Properties and the Microstructure of Isotactic Polypropylene/Bacterial Cellulose Composites

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2016-04-01

    Full Text Available Bacterial cellulose (BC has great potential to be used as a new filler to reinforce isotactic polypropylene (iPP due to its high crystallinity, biodegradability, and efficient mechanical properties. In this study, esterification was used to modify BC, which improved the surface compatibility of the iPP and BC. The results indicated that the cellulose octoate (CO changed the surface properties from hydrophilic to lipophilic. Compared to the pure iPP, the tensile strength, charpy notched impact strength, and tensile modulus of the iPP/BC composites increased by 9.9%, 7.77%, and 15.64%, respectively. However, the addition of CO reinforced the iPP/CO composites. The tensile strength, charpy notched impact strength, and tensile modulus of the iPP/CO composites increased by 14.23%, 14.08%, and 17.82% compared to the pure iPP. However, the elongation at break of both the composites is decreased. The SEM photographs and particle size distribution of the composites showed improvements when the change of polarity of the BC surface, interface compatibility, and dispersion of iPP improved.

  20. Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

    Directory of Open Access Journals (Sweden)

    Ying Deng

    Full Text Available Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC. These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of

  1. Isolation and Characterization of Two Cellulose Morphology Mutants of Gluconacetobacter hansenii ATCC23769 Producing Cellulose with Lower Crystallinity

    Science.gov (United States)

    Deng, Ying; Nagachar, Nivedita; Fang, Lin; Luan, Xin; Catchmark, Jeffrey M.; Tien, Ming; Kao, Teh-hui

    2015-01-01

    Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the

  2. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, Sara

    2015-05-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

  3. Evaluating the swelling, erosion, and compaction properties of cellulose ethers.

    Science.gov (United States)

    Ghori, Muhammad U; Grover, Liam M; Asare-Addo, Kofi; Smith, Alan M; Conway, Barbara R

    2018-02-01

    Swelling, erosion, deformation, and consolidation properties can affect the performance of cellulose ethers, the most commonly used matrix former in hydrophilic sustained tablet formulations. The present study was designed to comparatively evaluate the swelling, erosion, compression, compaction, and relaxation properties of the cellulose ethers in a comprehensive study using standardised conditions. The interrelationship between various compressional models and the inherent deformation and consolidation properties of the polymers on the derived swelling and erosion parameters are consolidated. The impact of swelling (K w ) on erosion rates (K E ) and the inter-relationship between Heckel and Kawakita plasticity constants was also investigated. It is evident from the findings that the increases in both substitution and polymer chain length led to higher K w , but a lower K E ; this was also true for all particle size fractions regardless of polymer grade. Smaller particle size and high substitution levels tend to increase the relative density of the matrix but reduce porosity, yield pressure (P y ), Kawakita plasticity parameter (b -1 ) and elastic relaxation. Both K W versus K E (R 2  = 0.949-0.980) and P y versus. b -1 correlations (R 2  = 0.820-0.934) were reasonably linear with regards to increasing hydroxypropyl substitution and molecular size. Hence, it can be concluded that the combined knowledge of swelling and erosion kinetics in tandem with the in- and out-of-die compression findings can be used to select a specific polymer grade and further to develop and optimize formulations for oral controlled drug delivery applications.

  4. Cellulose nanoparticles: photoacoustic contrast agents that biodegrade to simple sugars

    Science.gov (United States)

    Jokerst, Jesse V.; Bohndiek, Sarah E.; Gambhir, Sanjiv S.

    2014-03-01

    In photoacoustic imaging, nanoparticle contrast agents offer strong signal intensity and long-term stability, but are limited by poor biodistribution and clearance profiles. Conversely, small molecules offer renal clearance, but relatively low photoacoustic signal. Here we describe a cellulose-based nanoparticle with photoacoustic signal superior to gold nanorods, but that undergoes enzymatic cleavage into constituent glucose molecules for renal clearance. Cellulose nanoparticles (CNPs) were synthesized through acidic cleavage of cellulose linters and purified with centrifugation. TEM indicated that the nanoparticles were 132 +/- 46 nm; the polydispersity index was 0.138. Ex vivo characterization showed a photoacoustic limit of detection of 0.02 mg/mL CNPs, and the photoacoustic signal of CNPs was 1.5- to 3.0-fold higher than gold nanorods (also at 700 nm resonance) on a particle-to-particle basis. Cell toxicity assays suggested that overnight doses below 0.31 mg/mL CNPs produced no significant (p>0.05) impact on cell metabolism. Intravenous doses up to 0.24 mg were tolerated well in nude mice. Subcutaneous and orthotopic tumor xenografts of the OV2008 ovarian cancer cell line were then created in nude mice. Data was collected with a Nexus128 scanner from Endra LifeSciences. Spectral data used a LAZR system from Visualsonics both at 700 nm excitation. We injected CNPs (0.024 mg, 0.048 mg, and 0.80 mg) via tail vein and showed that the tumor photoacoustic signal reached maximum increase between 10 and 20 minutes. All injected concentrations were statistically (p0.96 suggesting quantitative signal. CNP biodegradation was demonstrated ex vivo with a glucose assay. CNPs in the presence of cellulase were reduced to free glucose in under than four hours. The glucose concentration before addition of cellulase was not detectable, but increased to 92.1 μg/mL in four hours. CNPs in the absence of cellulase did not produce glucose. Small fragments of nanoparticle in the

  5. Mechanical properties of cellulose nanomaterials studied by contact resonance atomic force microscopy

    Science.gov (United States)

    Ryan Wagner; Robert J. Moon; Arvind Raman

    2016-01-01

    Quantification of the mechanical properties of cellulose nanomaterials is key to the development of new cellulose nanomaterial based products. Using contact resonance atomic force microscopy we measured and mapped the transverse elastic modulus of three types of cellulosic nanoparticles: tunicate cellulose nanocrystals, wood cellulose nanocrystals, and wood cellulose...

  6. Effect of rheological properties of dissolved cellulose/microfibrillated cellulose blend suspensions on film forming.

    Science.gov (United States)

    Saarikoski, Eve; Rissanen, Marja; Seppälä, Jukka

    2015-03-30

    Enzymatically treated cellulose was dissolved in a NaOH/ZnO solvent system and mixed together with microfibrillated cellulose (MFC) in order to find the threshold in which MFC fibers form a percolation network within the dissolved cellulose solution and in order to improve the properties of regenerated cellulose films. In the aqueous state, correlations between the rheological properties of dissolved cellulose/MFC blend suspensions and MFC fiber concentrations were investigated and rationalized. In addition, rheological properties of diluted MFC suspensions were characterized and a correlation with NaOH concentration was found, thus partly explaining the flow properties of dissolved cellulose/MFC blend suspensions. Finally, based on results from Dynamic Mechanical Analysis (DMA), MFC addition had strengthening/plasticizing effect on regenerated cellulose films if low concentrations of MFC, below the percolation threshold (5.5-6 wt%, corresponding to 0.16-0.18 wt% of MFC in the blend suspensions), were used. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

    KAUST Repository

    Puspasari, Tiara

    2018-04-11

    Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration of trimethylsilyl cellulose (TMSC), an easily synthesized cellulose derivative. The amorphous hydrophilic feature of the regenerated cellulose enabled fast permeation of water vapour. The pore-free cellulose layer thickness was adjustable by the initial TMSC concentration and acted as an efficient gas barrier. As a result, a 5,000 GPU water vapour transmission rate (WVTR) at the highest ideal selectivity of 1.1 x 106 was achieved by the membranes spin coated from a 7% (w/w) TMSC solution. The membranes maintained a 4,000 GPU WVTR with selectivity of 1.1 x 104 in the mixed-gas experiments, surpassing the performances of the previously reported composite membranes. This study provides a simple way to not only produce high performance membranes but also to advance cellulose as a low-cost and sustainable membrane material for dehumidification applications.

  8. Cellulose nanocrystals, nanofibers, and their composites as renewable smart materials

    Science.gov (United States)

    Kim, Jaehwan; Zhai, Lindong; Mun, Seongcheol; Ko, Hyun-U.; Yun, Young-Min

    2015-04-01

    Cellulose is one of abundant renewable biomaterials in the world. Over 1.5 trillion tons of cellulose is produced per year in nature by biosynthesis, forming microfibrils which in turn aggregate to form cellulose fibers. Using new effective methods these microfibrils can be disintegrated from the fibers to nanosized materials, so called cellulose nanocrystal (CNC) and cellulose nanofiber (CNF). The CNC and CNF have extremely good strength properties, dimensional stability, thermal stability and good optical properties on top of their renewable behavior, which can be a building block of new materials. This paper represents recent advancement of cellulose nanocrystals and cellulose nanofibers, followed by their possibility for smart materials. Natural behaviors, extraction, modification of cellulose nanocrystals and fibers are explained and their synthesis with nanomaterials is introduced, which is necessary to meet the technological requirements for smart materials. Also, its challenges are addressed.

  9. Fabrication of water-repellent cellulose fiber coated with magnetic nanoparticles under supercritical carbon dioxide

    Science.gov (United States)

    Xu, Shengjie; Shen, Danping; Wu, Peiyi

    2013-04-01

    Hematite nanoparticle-coated magnetic composite fiber was prepared in supercritical carbon dioxide (scCO2). With the help of scCO2, cellulose did not need to be dissolved and regenerated and it could be in any form (e.g., cotton wool, filter paper, textile, etc.). The penetrating and swelling effect of scCO2, the slowing reaction rate of weak alkalis, and the template effect of cellulose fibers were discovered to be the key factors for the fabrication of ordered cellulose/Fe2O3 composite fibers. The structures of the composite fibers as well as the layers of Fe2O3 particles were characterized by means of scanning/transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman investigation. It was found that α-Fe2O3 granules which ranged from 30 to 85 nm with average diameter around 55 nm would be generated on the surface of cellulose fibers via potassium acetate, while irregular square prisms (ranged from 200 to 600 nm) which were composed of smaller nanoparticles ( 10 nm) would be fabricated via urea. And, the obtained composite was highly water repellent with superparamagnetic or ferromagnetic properties.

  10. Isolation of Nanocrystalline Cellulose from oil palm empty fruit bunch – A response surface methodology study

    Directory of Open Access Journals (Sweden)

    Song Yee Kai

    2016-01-01

    Full Text Available The research work studied the extraction of Nano Crystalline Cellulose (NCC from oil palm empty fruit bunch (EFB, with aid of Response Surface Methodology (RSM. Particle size analysis using Malvern Zetasizer had confirmed the extracted NCC fall within the desired nano scaled range. The impact of three input parameters, namely concentration of NaOH solution during alkaline treatment, concentration of H2SO4 solution during acid hydrolysis, and duration for acid hydrolysis on NCC particle were investigated. From ANOVA study, it had suggested that the current RSM model is significant to interpret the interaction among the all three input parameters.

  11. Evaluation of roll compaction as a preparation method for hydroxypropyl cellulose-based matrix tablets

    Directory of Open Access Journals (Sweden)

    Imjak Jeon

    2011-01-01

    Full Text Available Roll compaction was applied for the preparation of hydroxypropyl cellulose (HPC-based sustained-release matrix tablets. Matrix tablets made via roll compaction exhibited higher dosage uniformity and faster drug release than direct-compacted tablets. HPC viscosity grade, roll pressure, and milling speed affected tablet properties significantly. Roll compaction seems to be an adequate granulation method for the preparation of HPC-based matrix tablets due to the simplicity of the process, less handling difficulty from HPC tackiness as well as easier particle size targeting. Selecting the optimum ratio of plastic excipients and the particle size of starting materials can however be critical issues in this method.

  12. Cellulose acetobutyrate films and beryllium oxide discs for low-level radiation monitoring

    International Nuclear Information System (INIS)

    Ventura, S.A.; Kleinschmidt, D.E.; Mbu, J.B.

    1976-01-01

    The effect of mylar films on the attenuation of alpha particle energy and the production of etchable tracks in cellulose acetobutyrate was studied. A model developed predicts a 15-μ optimum mylar film thickness, while experimental results indicated a 22.8-μ optimum. The effect of alpha particle and potassium hydroxide solution interaction with CAB was reviewed and process improvements suggested. The TSEE response of BeO discs to tritium at 5.0 mCi/m 3 for up to 15-hr exposure was also investigated. An average TSEE/β ratio of 0.02 was obtained

  13. Prospects for Irradiation in Cellulosic Ethanol Production

    Directory of Open Access Journals (Sweden)

    Anita Saini

    2015-01-01

    Full Text Available Second generation bioethanol production technology relies on lignocellulosic biomass composed of hemicelluloses, celluloses, and lignin components. Cellulose and hemicellulose are sources of fermentable sugars. But the structural characteristics of lignocelluloses pose hindrance to the conversion of these sugar polysaccharides into ethanol. The process of ethanol production, therefore, involves an expensive and energy intensive step of pretreatment, which reduces the recalcitrance of lignocellulose and makes feedstock more susceptible to saccharification. Various physical, chemical, biological, or combined methods are employed to pretreat lignocelluloses. Irradiation is one of the common and promising physical methods of pretreatment, which involves ultrasonic waves, microwaves, γ-rays, and electron beam. Irradiation is also known to enhance the effect of saccharification. This review explains the role of different radiations in the production of cellulosic ethanol.

  14. Old Cellulose for New Multifunctional Networks

    Science.gov (United States)

    Yong, Geng

    Cellulose is considered to be the most abundant and renewable natural polymer on earth. It is the main component of plant cells. The exploration of the utility and applications of this material and its derivatives has never stopped since human's birth. It is well known that cellulose based materials can generate films and fibers, which can be, for instance, produced from cellulosic solutions. The Cellulose rich chemical structure allows different behaviors of the polymer in solution, which is the driving force for diverse films and fibers features. The main goal of this work is the manufacture and characterization of new application of the renewable cellulosic-based materials, which are at the origin of stimuli-responsive and/or functional soft films and fibers. The several materials obtained have in common the main chain cellulose backbone but present different liquid crystalline properties. Firstly rheology coupled to nuclear magnetic resonance techniques (rheo-NMR) were used to characterize a cellulose-water based liquid crystalline solution in order to establish structure/properties relationships, which were the basis to improve the design of films and fibers produced in the framework of this work. The results achieved were at the origin of a paper published in Macromolecules. Then films were produced and due to their structure and enhanced mechanical properties, different applications were realized by producing cellulosic gratings, which mimic the periodic structures that can be found in some petals of plants and a soft cellulose moisture motor was built for the first time. Two manuscripts were published, one related to the grating mimics, in Macromolecular Chemistry and Physics, and the other one dedicated to the mechanical properties and the bending of a cellulosic film controlled by moisture action in Scientific Reports (Nature Publishing Group). Concerning cellulosic fibers, two methods were selected to fabricate micro/nano networks. In order to produce

  15. Hydrogen bonds and twist in cellulose microfibrils.

    Science.gov (United States)

    Kannam, Sridhar Kumar; Oehme, Daniel P; Doblin, Monika S; Gidley, Michael J; Bacic, Antony; Downton, Matthew T

    2017-11-01

    There is increasing experimental and computational evidence that cellulose microfibrils can exist in a stable twisted form. In this study, atomistic molecular dynamics (MD) simulations are performed to investigate the importance of intrachain hydrogen bonds on the twist in cellulose microfibrils. We systematically enforce or block the formation of these intrachain hydrogen bonds by either constraining dihedral angles or manipulating charges. For the majority of simulations a consistent right handed twist is observed. The exceptions are two sets of simulations that block the O2-O6' intrachain hydrogen bond, where no consistent twist is observed in multiple independent simulations suggesting that the O2-O6' hydrogen bond can drive twist. However, in a further simulation where exocyclic group rotation is also blocked, right-handed twist still develops suggesting that intrachain hydrogen bonds are not necessary to drive twist in cellulose microfibrils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Process design and optimization of cellulose hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, R.R.; Wilke, C.R.

    1978-08-01

    The primary concern of this work is the economic optimization of a process for the hydrolysis of waste cellulosic material to fermentable sugars. Hydrolysis is performed enzymatically, utilizing the cellulase enzyme complex produced by Trichoderma viride. Using corn stover as a substrate, a system was designed to provide 14% hydrolyzate sugars (70% fermentable) at an estimated cost of 6.84 cents/pound of sugar, a 43% cost reduction over previous designs. Optimal residence time for hydrolysis was found to be 62 hours, resulting in a 34% conversion of raw material to sugars. Total fixed capital investment for the process is estimated to be $17.13 x 10/sup 6/. The kinetics of cellulose hydrolysis were modeled through the use of a modified Michaelis--Menten equation, making computer simulation of batch hydrolyses possible. Additional studies on the accessibility of cellulose were performed, and the feasibility of a counter-current processing scheme was investigated.

  17. Chemical genetics to examine cellulose biosynthesis

    Directory of Open Access Journals (Sweden)

    Seth eDebolt

    2013-01-01

    Full Text Available Long-term efforts to decode plant cellulose biosynthesis via molecular genetics and biochemical strategies are being enhanced by the ever-expanding scale of omics technologies. An alternative approach to consider are the prospects for inducing change in plant metabolism using exogenously supplied chemical ligands. Cellulose biosynthesis inhibitors (CBI have been identified among known herbicides, during diverse combinatorial chemical libraries screens, and natural chemical screens from microbial agents. In this review, we summarize the current knowledge of the inhibitory effects of CBIs and further group them by how they influence fluorescently tagged cellulose synthase A (CESA proteins. Additional attention is paid to the continuing development of the CBI toolbox to explore the cell biology and genetic mechanisms underpinning effector molecule activity.

  18. Tissue engineering scaffolds electrospun from cotton cellulose.

    Science.gov (United States)

    He, Xu; Cheng, Long; Zhang, Ximu; Xiao, Qiang; Zhang, Wei; Lu, Canhui

    2015-01-22

    Nonwovens of cellulose nanofibers were fabricated by electrospinning of cotton cellulose in its LiCl/DMAc solution. The key factors associated with the electrospinning process, including the intrinsic properties of cellulose solutions, the rotating speed of collector and the applied voltage, were systematically investigated. XRD data indicated the electrospun nanofibers were almost amorphous. When increasing the rotating speed of the collector, preferential alignment of fibers along the drawing direction and improved molecular orientation were revealed by scanning electron microscope and polarized FTIR, respectively. Tensile tests indicated the strength of the nonwovens along the orientation direction could be largely improved when collected at a higher speed. In light of the excellent biocompatibility and biodegradability as well as their unique porous structure, the nonwovens were further assessed as potential tissue engineering scaffolds. Cell culture experiments demonstrated human dental follicle cells could proliferate rapidly not only on the surface but also in the entire scaffold. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Alexa fluor-labeled fluorescent cellulose nanocrystals for bioimaging solid cellulose in spatially structured microenvironments.

    Science.gov (United States)

    Grate, Jay W; Mo, Kai-For; Shin, Yongsoon; Vasdekis, Andreas; Warner, Marvin G; Kelly, Ryan T; Orr, Galya; Hu, Dehong; Dehoff, Karl J; Brockman, Fred J; Wilkins, Michael J

    2015-03-18

    Methods to covalently conjugate Alexa Fluor dyes to cellulose nanocrystals, at limiting amounts that retain the overall structure of the nanocrystals as model cellulose materials, were developed using two approaches. In the first, aldehyde groups are created on the cellulose surfaces by reaction with limiting amounts of sodium periodate, a reaction well-known for oxidizing vicinal diols to create dialdehyde structures. Reductive amination reactions were then applied to bind Alexa Fluor dyes with terminal amino-groups on the linker section. In the absence of the reductive step, dye washes out of the nanocrystal suspension, whereas with the reductive step, a colored product is obtained with the characteristic spectral bands of the conjugated dye. In the second approach, Alexa Fluor dyes were modified to contain chloro-substituted triazine ring at the end of the linker section. These modified dyes then were reacted with cellulose nanocrystals in acetonitrile at elevated temperature, again isolating material with the characteristic spectral bands of the Alexa Fluor dye. Reactions with Alexa Fluor 546 are given as detailed examples, labeling on the order of 1% of the total glucopyranose rings of the cellulose nanocrystals at dye loadings of ca. 5 μg/mg cellulose. Fluorescent cellulose nanocrystals were deposited in pore network microfluidic structures (PDMS) and proof-of-principle bioimaging experiments showed that the spatial localization of the solid cellulose deposits could be determined, and their disappearance under the action of Celluclast enzymes or microbes could be observed over time. In addition, single molecule fluorescence microscopy was demonstrated as a method to follow the disappearance of solid cellulose deposits over time, following the decrease in the number of single blinking dye molecules with time instead of fluorescent intensity.

  20. Processing of cellulose for the advancement of biofuels

    Science.gov (United States)

    Watson, Brian James

    2011-12-01

    The enzymatic degradation of cellulose polymers is currently a rate-limiting step in the bioconversion of biomass to biofuels. Cellulose polymers self assemble to form crystalline structures stabilized by a complex network of intermolecular interactions such as hydrogen bonding. The network of interactions in crystalline cellulose (cellulose nanostructure) poses an energy barrier that limits enzymatic degradation as apparent from the activity of Cel5H. To improve the degradability of cellulose the intermolecular interactions must be disrupted. The interactions of the cellulose nanostructure prevent solubilization by water and most other common solvents, but some organic solvents aid degradation of cellulose suggesting they influence cellulose nanostructure. The objective of this work is to understand the influence of solvents on cellulose nanostructure with the goal of improving the degradability of cellulose nanostructure using solvents. To understand solvent interaction with cellulose, phosphoric acid was used to first solubilize cellulose (PAS cellulose) followed by adding an organic liquid or water to wash the phosphate from the system. The Flory Huggins theory was used to predict wash liquids that could favorably interact with cellulose. A favorable wash liquid was predicted to prevent the reformation of crystalline domains to yield a disrupted cellulose nanostructure, which should be more degradable. Low molecular weight alcohols and glycols were calculated to be favorable wash liquids. Washing PAS cellulose with the predicted favorable liquids yielded semi-transparent gel-like materials compared to the opaque white precipitate formed when water or unfavorable solvents were used in the wash. Fractal analysis of small angle neutron scattering (SANS) of these apparent gels indicated cellulose polymers likely have the properties of clustered rods. This partial disruption increased degradability relative to the water washed PAS cellulose. The apparent rod

  1. Graphene-Borate as an Efficient Fire Retardant for Cellulosic Materials with Multiple and Synergetic Modes of Action.

    Science.gov (United States)

    Nine, Md J; Tran, Diana N H; Tung, Tran Thanh; Kabiri, Shervin; Losic, Dusan

    2017-03-22

    To address high fire risks of flamable cellulosic materials, that can trigger easy combustion, flame propagation, and release of toxic gases, we report a new fire-retardant approach using synergetic actions combining unique properties of reduced graphene oxide (rGO) and hydrated-sodium metaborates (SMB). The single-step treatment of cellulosic materials by a composite suspension of rGO/SMB was developed to create a barrier layer on sawdust surface providing highly effective fire retardant protection with multiple modes of action. These performances are designed considering synergy between properties of hydrated-SMB crystals working as chemical heat-sink to slow down the thermal degradation of the cellulosic particles and gas impermeable rGO layers that prevents access of oxygen and the release of toxic volatiles. The rGO outer layer also creates a thermal and physical barrier by donating carbon between the flame and unburnt wood particles. The fire-retardant performance of developed graphene-borate composite and mechanism of fire protection are demonstrated by testing of different forms of cellulosic materials such as pine sawdust, particle-board, and fiber-based structures. Results revealed their outstanding self-extinguishing behavior with significant resistance to release of toxic and flammable volatiles suggesting rGO/SMB to be suitable alternative to the conventional toxic halogenated flame-retardant materials.

  2. Improvement of Piezoelectricity in Piezoelectric Paper Made With Cellulose

    Science.gov (United States)

    2009-11-25

    Cellulose microfibril has ordered crystalline regions and disordered regions. b. EAPap is made from cellulose paper on which gold electrodes are...Final Report: AOARD-084035 Improvement of Piezoelectricity in Piezoelectric Paper made with Cellulose •Prof. Jaehwan Kim Center for EAPap...webpage: www.EAPap.com ABSTRACT This report deals with the improvement of piezoelectricity in the piezoelectric paper made with cellulose

  3. 21 CFR 172.872 - Methyl ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number...

  4. Effect of γ-radiation on the saccharification of cellulose

    International Nuclear Information System (INIS)

    De la Rosa, A.M.; Banzon, R.B.; Abad, L.V.; Nuguid, Z.F.; Bulos, A.S.

    1985-01-01

    The effect of gamma radiation on the acid and saccharification of agricultural cellulosic wastes was investigated. Radiation doses of 200 KGy and higher significantly increased the saccharification of rice straw, rice hull and corn husk. The observed radiation effects varied with the cellulosic material. Rice straw exhibited the greatest radiosensitivity while rice hull showed the least susceptibility to gamma radiation. Possible mechanisms for the radiation-induced degradation of cellulose and agricultural cellulosic wastes are discussed. (author)

  5. Evaluation of Microflow Digital Imaging Particle Analysis for Sub-Visible Particles Formulated with an Opaque Vaccine Adjuvant.

    Directory of Open Access Journals (Sweden)

    Grant E Frahm

    Full Text Available Microflow digital imaging (MDI has become a widely accepted method for assessing sub-visible particles in pharmaceutical formulations however, to date; no data have been presented on the utility of this methodology when formulations include opaque vaccine adjuvants. This study evaluates the ability of MDI to assess sub-visible particles under these conditions. A Fluid Imaging Technologies Inc. FlowCAM® instrument was used to assess a number of sub-visible particle types in solution with increasing concentrations of AddaVax™, a nanoscale squalene-based adjuvant. With the objective (10X used and the limitations of the sensor resolution, the instrument was incapable of distinguishing between sub-visible particles and AddaVax™ droplets at particle sizes less than 5 μm. The instrument was capable of imaging all particle types assessed (polystyrene beads, borosilicate glass, cellulose, polyethylene protein aggregate mimics, and lysozyme protein aggregates at sizes greater than 5 μm in concentrations of AddaVax™ up to 50% (vol:vol. Reduced edge gradients and a decrease in measured particle sizes were noted as adjuvant concentrations increased. No significant changes in particle counts were observed for polystyrene particle standards and lysozyme protein aggregates, however significant reductions in particle counts were observed for borosilicate (80% of original and cellulose (92% of original particles. This reduction in particle counts may be due to the opaque adjuvant masking translucent particles present in borosilicate and cellulose samples. Although the results suggest that the utility of MDI for assessing sub-visible particles in high concentrations of adjuvant may be highly dependent on particle morphology, we believe that further investigation of this methodology to assess sub-visible particles in challenging formulations is warranted.

  6. Growth properties of Cellulomonas flavigena mutants affected in cellulose utilization.

    Science.gov (United States)

    Béguin, P; Eisen, H

    1978-01-01

    The role of cellobiose metabolism in cellulose utilization by Cellulomonas flavigena was investigated by studying mutants unable to grow on cellobiose or cellulose. The results show that the ability to utilize cellulose is strictly dependent on the ability to utilize cellobiose. PMID:415038

  7. Structural differences of xylans affect their interaction with cellulose

    NARCIS (Netherlands)

    Kabel, M.A.; Borne, van den H.; Vincken, J.P.; Voragen, A.G.J.; Schols, H.A.

    2007-01-01

    The affinity of xylan to cellulose is an important aspect of many industrial processes, e.g. production of cellulose, paper making and bio-ethanol production. However, little is known about the adsorption of structurally different xylans to cellulose. Therefore, the adsorption of various xylans to

  8. Nanotechnology : emerging applications of cellulose-based green magnetic nanocomposites

    Science.gov (United States)

    Tao Wang; Zhiyong Cai; Lei Liu; Ilker S. Bayer; Abhijit Biswas

    2010-01-01

    In recent years, a new type of nanocomposite – cellulose based hybrid nanocomposites, which adopts cellulose nanofibers as matrices, has been intensively developed. Among these materials, hybrid nanocomposites consisting of cellulosic fibers and magnetic nanoparticles have recently attracted much attention due to their potential novel applications in biomedicine,...

  9. Cyanobacterial cellulose synthesis in the light of the photanol concept

    NARCIS (Netherlands)

    Schuurmans, R.M.; Matthijs, H.C.P.; Stal, L.J.; Hellingwerf, K.J.; Sharma, N.K.; Rai, A.K.; Stal, L.J.

    2014-01-01

    The detailed knowledge already available about cellulose synthases and their regulation, plus emerging insights into the process of cellulose secretion in cyanobacteria make cellulose an attractive polymer for the application of the photanol concept in an economically viable production process. By

  10. Characterising the cellulose synthase complexes of cell walls

    NARCIS (Netherlands)

    Mansoori Zangir, N.

    2012-01-01

    One of the characteristics of the plant kingdom is the presence of a structural cell wall. Cellulose is a major component in both the primary and secondary cell walls of plants. In higher plants cellulose is synthesized by so called rosette protein complexes with cellulose synthases (CESAs) as

  11. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of this...

  12. Formation of Irreversible H-bonds in Cellulose Materials

    Science.gov (United States)

    Umesh P. Agarwal; Sally A. Ralph; Rick S. Reiner; Nicole M. Stark

    2015-01-01

    Understanding of formation of irreversible Hbonds in cellulose is important in a number of fields. For example, fields as diverse as pulp and paper and enzymatic saccharification of cellulose are affected. In the present investigation, the phenomenon of formation of irreversible H-bonds is studied in a variety of celluloses and under two different drying conditions....

  13. Characterising the cellulose synthase complexes of cell walls

    NARCIS (Netherlands)

    Mansoori Zangir, N.

    2012-01-01

    One of the characteristics of the plant kingdom is the presence of a structural cell wall. Cellulose is a major component in both the primary and secondary cell walls of plants. In higher plants cellulose is synthesized by so called rosette protein complexes with cellulose synthases (CESAs) as the

  14. Enzymatic saccharification of some agro-industrial cellulosic wastes ...

    African Journals Online (AJOL)

    Enzymatic saccharification of some agro-industrial cellulosic wastes by cellulose produced from a mixed culture of Aspergillus Niger and Saccharomyces ... All the sorghum pomace media recorded significantly (P<0.05) higher level of cellulase enzyme (2.06-4.06 units/ml) than that of carboxymethyl-cellulose medium (1.72 ...

  15. Plackett-Burman experimental design for bacterial cellulose-silica composites synthesis.

    Science.gov (United States)

    Guzun, Anicuta Stoica; Stroescu, Marta; Jinga, Sorin Ion; Voicu, Georgeta; Grumezescu, Alexandru Mihai; Holban, Alina Maria

    2014-09-01

    Bacterial cellulose-silica hybrid composites were prepared starting from wet bacterial cellulose (BC) membranes using Stöber reaction. The structure and surface morphology of hybrid composites were examined by FTIR and SEM. The SEM pictures revealed that the silica particles are attached to BC fibrils and are well dispersed in the BC matrix. The influence of silica particles upon BC crystallinity was studied using XRD analysis. Thermogravimetric (TG) analysis showed that the composites are stable up to 300°C. A Plackett-Burman design was applied in order to investigate the influence of process parameters upon silica particle sizes and silica content of BC-silica composites. The statistical model predicted that it is possible for silica particles size to vary the synthesis parameters in order to obtain silica particles deposed on BC membranes in the range from 34.5 to 500 nm, the significant parameters being ammonia concentration, reaction time and temperature. The silica content also varies depending on process parameters, the statistical model predicting that the most influential parameters are water-tetraethoxysilane (TEOS) ratio and reaction temperature. The antimicrobial behavior on Staphylococcus aureus of BC-silica composites functionalized with usnic acid (UA) was also studied, in order to create improved surfaces with antiadherence and anti-biofilm properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Method for separating the non-inked cellulose fibers from the inked cellulose fibers in cellulosic materials

    Science.gov (United States)

    Woodward, J.

    1998-12-01

    A method for enzymatically separating the non-inked cellulose fibers from the inked cellulose fibers in cellulosic materials. The cellulosic material, such as newsprint, is introduced into a first chamber containing a plastic canvas basket. This first chamber is in fluid communication, via plastic tubing, with a second chamber containing cellobiase beads in a plastic canvas basket. Cellulase is then introduced into the first chamber. A programmable pump then controls the flow rate between the two chambers. The action of cellulase and stirring in the first chamber results in the production of a slurry of newsprint pulp in the first chamber. This slurry contains non-inked fibers, inked fibers, and some cellobiose. The inked fibers and cellobiose flow from the first chamber to the second chamber, whereas the non-inked fibers remain in the first chamber because they are too large to pass through the pores of the plastic canvas basket. The resulting non-inked and inked fibers are then recovered. 6 figs.

  17. Nano-cellulose derived bioplastic biomaterial data for vehicle bio-bumper from banana peel waste biomass.

    Science.gov (United States)

    Sharif Hossain, A B M; Ibrahim, Nasir A; AlEissa, Mohammed Saad

    2016-09-01

    The innovative study was carried out to produce nano-cellulose based bioplastic biomaterials for vehicle use coming after bioprocess technology. The data show that nano-cellulose particle size was 20 nm and negligible water absorption was 0.03% in the bioplastic. Moreover, burning test, size and shape characterizations, spray coating dye, energy test and firmness of bioplastic have been explored and compared with the standardization of synthetic vehicle plastic bumper following the American Society for Testing and Materials (ASTM). Tensile test was observed 120 MPa/kg m(3). In addition to that pH and cellulose content were found positive in the bioplastic compared to the synthetic plastic. Chemical tests like K, CO3, Cl2, Na were determined and shown positive results compared to the synthetic plastic using the EN-14214 (European Norm) standardization.

  18. In-situ deposition of hematite (α-Fe2O3) microcubes on cotton cellulose via hydrothermal method

    Science.gov (United States)

    Gili, M.; Latag, G.; Balela, M.

    2018-03-01

    Hematite microcubes with truncated edges have been successfully deposited on cotton cellulose via one-step hydrothermal process using anhydrous FeCl3 and glycine as Fe(III) precursor and chelating agent, respectively. The amount of glycine significantly affects the morphology and yield of hematite. The addition of 0.495 g of glycine to 50 ml of 0.1 M FeCl3 solution with 0.400 g of cotton resulted to hematite-deposited cellulose having ∼15% hematite content. The reduction of glycine to 0.247 g increased the amount of hematite on the surface of the cotton cellulose to ∼20% by weight. However, the hematite microcubes have a wide size distribution, with particle size in the range of 0.684 μm to 1.520 μm. Without glycine, hematite cannot be formed in the solution.

  19. Cellulose Nanocrystals vs. Cellulose Nanofibrils: A Comparative study on Their Microstructures and Effects as Polymer Reinforcing Agents

    Science.gov (United States)

    Xuezhu Xu; Fei Liu; Long Jiang; J.Y. Zhu; Darrin Haagenson; Dennis P. Wiesenborn

    2013-01-01

    Both cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) are nanoscale cellulose fibers that have shown reinforcing effects in polymer nanocomposites. CNCs and CNFs are different in shape, size and composition. This study systematically compared their morphologies, crystalline structure, dispersion properties in polyethylene oxide (PEO) matrix, interactions...

  20. Chapter 2.1 Integrated Production of Cellulose Nanofibrils and Cellulosic Biofuel by Enzymatic Hydrolysis of wood Fibers

    Science.gov (United States)

    Ronald Sabo; J.Y. Zhu

    2013-01-01

    One key barrier to converting woody biomass to biofuel through the sugar platform is the low efficiency of enzymatic cellulose saccharification due to the strong recalcitrance of the crystalline cellulose. Significant past research efforts in cellulosic biofuels have focused on overcoming the recalcitrance of lignocelluloses to enhance the saccharification of...

  1. Mechanochemical radical formation in cellulose ball milling and production of cellulose-metal nanoparticles composites

    OpenAIRE

    Bayrak, Özge

    2017-01-01

    Cataloged from PDF version of article. Thesis (M.S.): Bilkent University, Department of Chemistry, İhsan Doğramacı Bilkent University, 2017. Includes bibliographical references (leaves 119-136). Cellulose is the most abundant biopolymer in nature, which contains linear chains of repeating D-glucose molecules connected by -1,4-glycosidic linkages. Over the past decades, due to growing interest in sustainability and green chemistry, cellulosic materials have received much attention. S...

  2. The improvement in functional characteristics of eco-friendly composites made of natural rubber and cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Kunihiro; Kaneko, Shonosuke; Matsumoto, Koki; Tanaka, Tatsuya; Arao, Yoshihiko [Applied Materials Engineering Laboratory, Faculty of Engineering, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto, 610-0321 (Japan); Nagatani, Asahiro [Applied Materials Engineering Laboratory, Faculty of Engineering, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto, 610-0321 (Japan); Hyogo Prefectural Institute of Technology, 3-1-12, Yukihira-cho, Suma-ku, Kobe, Hyogo, 654-0037 (Japan)

    2015-05-22

    We investigated the efficient use of cellulose to resolve the problem of the depletion of fossil resources. In this study, as the biomass material, the green composite based on natural rubber (NR) and the flake-shaped cellulose particles (FSCP) was produced. In order to further improvement of functional characteristics, epoxidized natural rubber (ENR) was also used instead of NR. The FSCP were produced by mechanical milling in a planetary ball mill with a grinding aid as a cellulose aggregation inhibitor. Moreover, talc and mica particles were used to compare with FSCP. NR and ENR was mixed with vulcanizing agents and then each filler was added to NR compound in an internal mixer. The vulcanizing agents are as follows: stearic acid, zinc oxide, sulfur, and vulcanization accelerator. The functionalities of the composites were evaluated by a vibration-damping experiment and a gas permeability experiment. As a result, we found that FSCP filler has effects similar to (or more than) inorganic filler in vibration-damping and O{sub 2} barrier properties. And then, vibration- damping and O{sub 2} barrier properties of the composite including FSCP was increased with use of ENR. In particular, we found that ENR-50 composite containing 50 phr FSCP has three times as high vibration-damping property as ENR-50 without FSCP.

  3. Antibacterial activity of silver nanoparticles synthesized In-situ by solution spraying onto cellulose.

    Science.gov (United States)

    Yan, Jinhua; Abdelgawad, Abdelrahman M; El-Naggar, Mehrez E; Rojas, Orlando J

    2016-08-20

    Spray technique was used for the adsorption of in-situ silver nanoparticles (AgNPs) onto and inside the surface of nano- and micro- fibrillar cellulose (NFC and MFC) as well as filter paper. The abundance of hydroxyl and carboxyl groups located in NFC and MFC are used to stabilize Ag ions (Ag(+)) which were then in-situ reduced to (AgNPs) by chemical or UV reduction. The surface characteristic features, elemental analysis, particle size as well as size distribution of the obtained MFC, NFC and filter paper loaded with AgNPs were characterized via field emission scanning electron microscopy connected to energy dispersive X-ray spectroscopy (FESEM- EDX) and transmission electron microscopy (TEM). The associated chemical changes after growth of AgNPs onto the cellulose substrates were assessed by fourier transform infra-red (FT-IR) while the thermal stability of such systems were investigated by thermogravimetrical analyses (TGA). The antibacterial properties of AgNPs loaded NFC, MFC and filter paper as well was investigated against Escherichia Coli. The resulted data indicate that the particle size was found to be 11 and 26nm for AgNPs nucleated on NFC and MFC-based papers respectively. The antibacterial activity of AgNPs loaded MFC exhibited higher antibacterial activity than that of AgNPs loaded NFC. Overall, the present research demonstrates facile and fast method for in-situ antibacterial AgNPs loading on cellulose substrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Simultaneous determination of Rn-220 and Rn-222 concentrations in atmospheres by cellulose nitrate ionographic detectors

    International Nuclear Information System (INIS)

    Lobao, N.

    1977-01-01

    A method for the indoor determination of airborne radon and radon daughters is described, based in the utilization of cellulose nitrate (CN) ionographic detectors (LR-115-Kodak-Pathe) These track-etching detectors are coupled to an air sample and to a difusion chamber respectively. In the first system ambient air is pulled through a fiber glass filter for collection of airborne radon daughters (Flow: 230 ml/min). In the second system, the cellulose nitrate detectors is coupled/min). In the second system, the cellulose nitrate detectors is coupled to a difusion chamber electrostatic precipitator arrangement. Here the CN detector will register only the alpha particles given off by the decay products of Rn-222 formed within the sensitive volume of electrostatic precipitator. The construction of calibration curves for the two systems using adequate steady-state concentrations of Rn-220 and Rn-222 in an exposure chamber (1 cubic meter), will allow the use of the system for measurement of measurement of averaged integrated radon concentrations. The CN attached to the CN attached to the air sampler is exposed in the reference atmosphere with and without a mylar filter for discrimination of alpha particles with different energies Field sampling indicated however, that efficiency of the two systems are still low for the measurement of environmental levels of Rn-220 and Rn-222 within houses of the AENR, recommendations for efficienty improvement of the system are proposed [pt

  5. Biodegradation behaviors of cellulose nanocrystals -PVA nanocomposites

    Directory of Open Access Journals (Sweden)

    Mahdi Rohani

    2014-11-01

    Full Text Available In this research, biodegradation behaviors of cellulose nanocrystals-poly vinyl alcohol nanocomposites were investigated. Nanocomposite films with different filler loading levels (3, 6, 9 and 12% by wt were developed by solvent casting method. The effect of cellulose nanocrystals on the biodegradation behaviors of nanocomposite films was studied. Water absorption and water solubility tests were performed by immersing specimens into distilled water. The characteristic parameter of diffusion coefficient and maximum moisture content were determined from the obtained water absorption curves. The water absorption behavior of the nanocomposites was found to follow a Fickian behavior. The maximum water absorption and diffusion coefficients were decreased by increasing the cellulose nanocrystals contents, however the water solubility decrease. The biodegradability of the films was investigated by immersing specimens into cellulase enzymatic solution as well as by burial in soil. The results showed that adding cellulose nanocrystals increase the weight loss of specimens in enzymatic solution but decrease it in soil media. The limited biodegradability of specimens in soil media attributed to development of strong interactions with solid substrates that inhibit the accessibility of functional groups. Specimens with the low degree of hydrolysis underwent extensive biodegradation in both enzymatic and soil media, whilst specimens with the high degree of hydrolysis showed recalcitrance to biodegradation under those conditions.

  6. African perspective on cellulosic ethanol production

    DEFF Research Database (Denmark)

    Bensah, Edem Cudjoe; Kemausuor, Francis; Miezah, Kodwo

    2015-01-01

    A major challenge to commercial production of cellulosic ethanol pertains to the cost-effective breakdown of the complex and recalcitrant structure of lignocellulose into its components via pretreatment, the cost of enzymes for hydrolysis and fermentation, and the conversion rate of C5 sugars to ...

  7. Methacrylate hydrogels reinforced with bacterial cellulose

    Czech Academy of Sciences Publication Activity Database

    Hobzová, Radka; Dušková-Smrčková, Miroslava; Michálek, Jiří; Karpushkin, Evgeny; Gatenholm, P.

    2012-01-01

    Roč. 61, č. 7 (2012), s. 1193-1201 ISSN 0959-8103 R&D Projects: GA AV ČR KJB400500902 Institutional research plan: CEZ:AV0Z40500505 Keywords : bacterial cellulose * methacrylate hydrogel * composite Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.125, year: 2012

  8. Rapid saccharification for production of cellulosic biofuels.

    Science.gov (United States)

    Lee, Dae-Seok; Wi, Seung Gon; Lee, Soo Jung; Lee, Yoon-Gyo; Kim, Yeong-Suk; Bae, Hyeun-Jong

    2014-04-01

    The economical production of biofuels is hindered by the recalcitrance of lignocellulose to processing, causing high consumption of processing enzymes and impeding hydrolysis of pretreated lignocellulosic biomass. We determined the major rate-limiting factor in the hydrolysis of popping pre-treated rice straw (PPRS) by examining cellulase adsorption to lignin and cellulose, amorphogenesis of PPRS, and re-hydrolysis. Based on the results, equivalence between enzyme loading and the open structural area of cellulose was required to significantly increase productive adsorption of cellulase and to accelerate enzymatic saccharification of PPRS. Amorphogenesis of PPRS by phosphoric acid treatment to expand open structural area of the cellulose fibers resulted in twofold higher cellulase adsorption and increased the yield of the first re-hydrolysis step from 13% to 46%. The total yield from PPRS was increased to 84% after 3h. These results provide evidence that cellulose structure is one of major effects on the enzymatic hydrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Water absorption and maintenance of nanofiber cellulose ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-05-17

    May 17, 2012 ... emulsions in cosmetics, repairs of old documents, coating compositions, food additives and temporary artificial skin. (Jonas and Farah, 1998). .... and its nanocomposites for biomedical applications, Cellulose nanocomposites, Oksman K, Sain M (eds). American Chem. Society,. Washington, DC. pp.

  10. Water absorption and maintenance of nanofiber cellulose ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-05-17

    May 17, 2012 ... Department of Food Science and Nutrition, Catholic University of Daegu, Gyeongsan 712-702, Korea. Accepted 13 ... culture. Bacterial cellulose acts as a floatation device supplying the bacteria to the oxygen rich air-media inter- face and also act as protecting device from UV light. (Ross et al., 1996).

  11. Cellulose acetate electrospun nanofibrous membrane: fabrication ...

    Indian Academy of Sciences (India)

    Cellulose-based materials are one of the most commonly used materials for biomedical applications, which normally applied as carriers for ... chitosan, chitin, polystyrene, polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polylactic ... Product Inc., USA) was used to investigate the wettability properties of the fibres. Briefly ...

  12. Degradation of cellulose by basidiomycetous fungi

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Valášková, Vendula

    2008-01-01

    Roč. 32, č. 3 (2008), s. 501-521 ISSN 0168-6445 R&D Projects: GA MŠk LC06066; GA MZe QH72216 Institutional research plan: CEZ:AV0Z50200510 Keywords : cellobiohydrolase * cellulose dehydrogenase * basidiomycetes Subject RIV: EE - Microbiology, Virology Impact factor: 7.963, year: 2008

  13. Evaluation of drug interactions with nanofibrillar cellulose.

    Science.gov (United States)

    Kolakovic, Ruzica; Peltonen, Leena; Laukkanen, Antti; Hellman, Maarit; Laaksonen, Päivi; Linder, Markus B; Hirvonen, Jouni; Laaksonen, Timo

    2013-11-01

    Nanofibrillar cellulose (NFC) (also referred to as cellulose nanofibers, nanocellulose, microfibrillated, or nanofibrillated cellulose) has recently gotten wide attention in various research areas and it has also been studied as excipient in formulation of the pharmaceutical dosage forms. Here, we have evaluated the interactions between NFC and the model drugs of different structural characteristics (size, charge, etc.). The series of permeation studies were utilized to evaluate the ability of the drugs in solution to diffuse through the thin, porous, dry NFC films. An incubation method was used to determine capacity of binding of chosen model drugs to NFC as well as isothermal titration calorimetry (ITC) to study thermodynamics of the binding process. A genetically engineered fusion protein carrying double cellulose binding domain was used as a positive control since its affinity and capacity of binding for NFC have already been reported. The permeation studies revealed the size dependent diffusion rate of the model drugs through the NFC films. The results of both binding and ITC studies showed that the studied drugs bind to the NFC material and indicated the pH dependence of the binding and electrostatic forces as the main mechanism. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Cellulose acetate electrospun nanofibrous membrane: fabrication ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Bulletin of Materials Science; Volume 39; Issue 2. Cellulose acetate electrospun nanofibrous membrane: fabrication, characterization, drug loading and antibacterial properties. NAZNIN SULTANA ... The CA nanofibrous membrane was non-toxic to human skin fibroblast cells. Thus the CA ...

  15. High-Performance Cellulose Nanofibril Composite Films

    Science.gov (United States)

    Yan Qing; Ronald Sabo; Yiqiang Wu; Zhiyong Cai

    2012-01-01

    Cellulose nanofibril/phenol formaldehyde (CNF/PF) composite films with high work of fracture were prepared by filtering a mixture of 2,2,6,6tetramethylpiperidine-1-oxyl (TEMPO) oxidized wood nanofibers and water-soluble phenol formaldehyde with resin contents ranging from 5 to 20 wt%, followed by hot pressing. The composites were characterized by tensile testing,...

  16. diffusion of metronidazole released through cellulose membrane

    African Journals Online (AJOL)

    prof kokwaro

    Three different topical formulations namely gel, cream and ointment, each containing 1% w/w metronidazole, were prepared and in vitro permeation studies carried out. The permeation of metronidazole from each of the topical formulation was determined using dialyzing cellulose membrane in a dissolution tester. Glycerin,.

  17. Dynamics of water bound to crystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    O’Neill, Hugh; Pingali, Sai Venkatesh; Petridis, Loukas; He, Junhong; Mamontov, Eugene; Hong, Liang; Urban, Volker; Evans, Barbara; Langan, Paul; Smith, Jeremy C.; Davison, Brian H.

    2017-09-19

    Interactions of water with cellulose are of both fundamental and technological importance. Here, we characterize the properties of water associated with cellulose using deuterium labeling, neutron scattering and molecular dynamics simulation. Quasi-elastic neutron scattering provided quantitative details about the dynamical relaxation processes that occur and was supported by structural characterization using small-angle neutron scattering and X-ray diffraction. We can unambiguously detect two populations of water associated with cellulose. The first is “non-freezing bound” water that gradually becomes mobile with increasing temperature and can be related to surface water. The second population is consistent with confined water that abruptly becomes mobile at ~260 K, and can be attributed to water that accumulates in the narrow spaces between the microfibrils. Quantitative analysis of the QENS data showed that, at 250 K, the water diffusion coefficient was 0.85 ± 0.04 × 10-10 m2sec-1 and increased to 1.77 ± 0.09 × 10-10 m2sec-1 at 265 K. MD simulations are in excellent agreement with the experiments and support the interpretation that water associated with cellulose exists in two dynamical populations. Our results provide clarity to previous work investigating the states of bound water and provide a new approach for probing water interactions with lignocellulose materials.

  18. A Sorption Hysteresis Model For Cellulosic Materials

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Damkilde, Lars

    2006-01-01

    The equilibrium concentration of adsorbed water in cellulosic materials is dependent on the history of the variations of vapor pressure in the ambient air, i.e. sorption hysteresis. Existing models to describe this phenomenon such as the independent domain theory have numerical drawbacks and/or i...

  19. Cellulose based polymeric systems in drug delivery

    Science.gov (United States)

    The pharmaceutical industry requires the development of biodegradable, biocompatible, non toxic, site specific drug delivery polymers, which can be easily coupled with drugs to be delivered orally, topically, locally, or parenterally. The use of the most abundant biopolymer, cellulose along with its...

  20. Structural and morphological characterization of cellulose pulp

    CSIR Research Space (South Africa)

    Ocwelwang, A

    2015-09-01

    Full Text Available International Symposium on Wood, Fibre and Pulping Chemistry, BOKU University, Vienna, Austria, 09-11th September 2015 9-11 September 2015 Structural and morphological characterization of cellulose pulp Atsile Ocwelwang1,2,*Bruce Sithole1,2, Deresh...

  1. Atomic force microscopy characterization of cellulose nanocrystals

    Science.gov (United States)

    Roya R. Lahiji; Xin Xu; Ronald Reifenberger; Arvind Raman; Alan Rudie; Robert J. Moon

    2010-01-01

    Cellulose nanocrystals (CNCs) are gaining interest as a “green” nanomaterial with superior mechanical and chemical properties for high-performance nanocomposite materials; however, there is a lack of accurate material property characterization of individual CNCs. Here, a detailed study of the topography, elastic and adhesive properties of individual wood-derived CNCs...

  2. Nanomanufacturing metrology for cellulosic nanomaterials: an update

    Science.gov (United States)

    Postek, Michael T.

    2014-08-01

    The development of the metrology and standards for advanced manufacturing of cellulosic nanomaterials (or basically, wood-based nanotechnology) is imperative to the success of this rising economic sector. Wood-based nanotechnology is a revolutionary technology that will create new jobs and strengthen America's forest-based economy through industrial development and expansion. It allows this, previously perceived, low-tech industry to leap-frog directly into high-tech products and processes and thus improves its current economic slump. Recent global investments in nanotechnology programs have led to a deeper appreciation of the high performance nature of cellulose nanomaterials. Cellulose, manufactured to the smallest possible-size ( 2 nm x 100 nm), is a high-value material that enables products to be lighter and stronger; have less embodied energy; utilize no catalysts in the manufacturing, are biologically compatible and, come from a readily renewable resource. In addition to the potential for a dramatic impact on the national economy - estimated to be as much as $250 billion worldwide by 2020 - cellulose-based nanotechnology creates a pathway for expanded and new markets utilizing these renewable materials. The installed capacity associated with the US pulp and paper industry represents an opportunity, with investment, to rapidly move to large scale production of nano-based materials. However, effective imaging, characterization and fundamental measurement science for process control and characterization are lacking at the present time. This talk will discuss some of these needed measurements and potential solutions.

  3. Pyrolysis-crystallinity relationships in cellulose

    Science.gov (United States)

    M. Weinstein; A. Broido

    1970-01-01

    During pyrolysis of pure cellulose, the Crystallinity Index (Crl) remained fairly constant over more than 50% weight loss before dropping rapidly as the X-ray pattern deteriorated. With samples first treated with trace quantities of inorganic salts, heating first increased the Crl—the results implying a preferentially catalyzed decomposition of the amorphous regions....

  4. Chemistry, Technology and Aplications of Oxidized Celluloses

    Czech Academy of Sciences Publication Activity Database

    Havelka, P.; Sopuch, T.; Hnatowicz, Vladimír; Suchý, P.; Masteikova, R.; Bajerová, M.; Gajdziok, J.; Milichovský, M.; Švorčík, V.

    2010-01-01

    Roč. 2010, C (2010), s. 205-245. ISBN 978-1-608-76-388-7 Institutional support: RVO:61389005 Keywords : oxidation * cellulose * in-vitro Subject RIV: BO - Biophysics https://www.novapublishers.com/catalog/product_info.php?products_id=14049

  5. Method of forming an electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN; Woodward, Jonathan [Ashtead, GB

    2011-11-22

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  6. Micropatterned thin film honeycomb materials from regiospecifically modified cellulose.

    Science.gov (United States)

    Kadla, John F; Asfour, Fadi H; Bar-Nir, Batia

    2007-01-01

    Thin film honeycomb materials were prepared from regioselectively modified celluloses. The method uses water condensation at the surface of a cellulosic solution as an ordered template to form honeycomb structures. Pore size and distribution is controlled by several factors, one of which is the hydrophilicity of the cellulosic used. The amphiphilic nature of the celluloses was modified with varying lengths of ethylene glycol side chains using 2,6-thexyldimethylsilyl cellulose. It was found that the side chains do affect the honeycomb formation, with longer ethylene glycol chains leading to increased pore uniformity but having little influence on the pore size.

  7. Pretreatment assisted synthesis and characterization of cellulose nanocrystals and cellulose nanofibers from absorbent cotton.

    Science.gov (United States)

    Abu-Danso, Emmanuel; Srivastava, Varsha; Sillanpää, Mika; Bhatnagar, Amit

    2017-09-01

    In this work, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were synthesized from absorbent cotton. Two pretreatments viz. dewaxing and bleaching with mild alkali were applied to the precursor (cotton). Acid hydrolysis was conducted with H 2 SO 4 and dissolution of cotton was achieved with a mixture of NaOH-thiourea-urea-H 2 O at -3°C. Synthesized cellulose samples were characterized using FTIR, XRD, SEM, BET, and zeta potential. It seems that synthesis conditions contributed to negative surface charge on cellulose samples and CNCs had the higher negative surface charge compared to CNFs. Furthermore, BET surface area, pore volume and pore diameter of CNCs were found to be higher as compared to CNFs. The dewaxed cellulose nanofibers (CNF D) had a slightly higher BET surface area (0.47m 2 /g) and bigger pore diameter (59.87Å) from attenuated contraction compared to waxed cellulose nanofibers (CNFW) (0.38m 2 /g and 44.89Å). The XRD of CNCs revealed a semi-crystalline structure and the dissolution agents influenced the crystallinity of CNFs. SEM images showed the porous nature of CNFs, the flaky nature and the nano-sized width of CNCs. Synthesized CNF D showed a better potential as an adsorbent with an average lead removal efficiency of 91.49% from aqueous solution. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Coating of cellulose-TiO2 nanoparticles on cotton fabric for durable photocatalytic self-cleaning and stiffness.

    Science.gov (United States)

    Kale, Bandu Madhukar; Wiener, Jakub; Militky, Jiri; Rwawiire, Samson; Mishra, Rajesh; Jacob, Karl I; Wang, Youjiang

    2016-10-05

    A new route to make cotton fabric self-cleaning and permanently stiff by coating cellulose-TiO2 on its surface is demonstrated herein. Cellulose-TiO2 dispersion was used for coating and was prepared by mixing TiO2 nanoparticles with cellulose in 60% H2SO4 solution. The surface morphology of cellulose-TiO2 nanoparticles coated sample was analyzed by SEM. The appearance of white TiO2 particles on the surface of the cotton fabric confirmed the successful coating process. The Orange II dye was used as stain and its degradation was observed under UV light. X-ray diffraction analysis showed that cellulose II content increases slightly (by 5.3%) after the solvent treatment. Washing fastness study showed that the fabric stiffness was permanent and self-cleaning properties were stable with 1, 3 and 5% TiO2 coated samples. Air and water vapor permeability was not decreased considerably, whereas tensile strength was increased significantly after coating. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. On the polymorphic and morphological changes of cellulose nanocrystals (CNC-I) upon mercerization and conversion to CNC-II.

    Science.gov (United States)

    Jin, Ersuo; Guo, Jiaqi; Yang, Fang; Zhu, Yangyang; Song, Junlong; Jin, Yongcan; Rojas, Orlando J

    2016-06-05

    Polymorphic and morphological transformations of cellulosic materials are strongly associated to their properties and applications, especially in the case of emerging nanocelluloses. Related changes that take place upon treatment of cellulose nanocrystals (CNC) in alkaline conditions are studied here by XRD, TEM, AFM, and other techniques. The results indicate polymorphic transformation of CNC proceeds gradually in a certain range of alkali concentrations, i.e. from about 8% to 12.5% NaOH. In such transition alkali concentration, cellulose I and II allomorphs coexists. Such value and range of the transition concentration is strongly interdependent with the crystallite size of CNCs. In addition, it is distinctively lower than that for macroscopic fibers (12-15% NaOH). Transmission electron microscopy and particle sizing reveals that after mercerization CNCs tend to associate. Furthermore, TEMPO-oxidized mercerized CNC reveals the morphology of individual nanocrystal of the cellulose II type, which is composed of some interconnected granular structures. Overall, this work reveals how the polymorphism and morphology of individual CNC change in alkali conditions and sheds light onto the polymorphic transition from cellulose I to II. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. The Synthesis of a Novel Cellulose Physical Gel

    Directory of Open Access Journals (Sweden)

    Jiufang Duan

    2014-01-01

    Full Text Available Cellulose possessing β-cyclodextrin (β-CD was used as a host molecule and cellulose possessing ferrocene (Fc as a guest polymer. Infrared spectra, differential scanning calorimetry (DSC, ultraviolet spectroscopy (UV, and contact angle analysis were used to characterise the material structure and the inclusion behaviour. The results showed that the β-CD-cellulose and the Fc-cellulose can form inclusion complexes. Moreover, ferrocene oxidation, and reduction of state can be adjusted by sodium hypochlorite (NaClO as an oxidant and glutathione (GSH as a reductant. In this study, a physical gel based on β-CD-cellulose/Fc-cellulose was formed under mild conditions in which autonomous healing between cut surfaces occurred after 24 hours. The physical gel can be controlled in the sol-gel transition. The compressive strength of the Fc-cellulose/β-CD-cellulose gel increased with increased cellulose concentration. The host-guest interaction between the side chains of cellulose could strengthen the gel. The cellulose physical gel may eventually be used as a stimulus-responsive, healing material in biomedical applications.

  11. Assessing nano cellulose developments using science and technology indicators

    International Nuclear Information System (INIS)

    Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues

    2013-01-01

    This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

  12. Characterization of cellulose extracted from oil palm empty fruit bunch

    Science.gov (United States)

    Sisak, Muhammad Asri Abdul; Daik, Rusli; Ramli, Suria

    2015-09-01

    Recently, cellulose has been studied by many researchers due to its promising properties such as biodegradability, biocompatibility, hydrophilicity and robustness. Due to that it is applied in many fields such as paper, film, drug delivery, membranes, etc. Cellulose can be extracted from various plants while oil palm empty fruit bunch (OPEFB) is the one of its sources. In this study, cellulose was extracted by chemical treatments which involved the use of formic acid and hydrogen peroxide to remove hemicellulose and lignin components. Maximum yield was 43.22%. Based on the FT-IR spectra, the peak of wax (1735 cm-1), hemicellulose (1375 cm-1) and lignin (1248 cm-1 and 1037 cm-1) were not observed in extracted cellulose. TGA analysis showed that the extracted cellulose starts to thermally degrade at 340 °C. The SEM analysis suggested that the cellulose extracted from OPEFB was not much different from commercial cellulose.

  13. Nanofibers of Cellulose and Its Derivatives Fabricated Using Direct Electrospinning

    Directory of Open Access Journals (Sweden)

    Kousaku Ohkawa

    2015-05-01

    Full Text Available A short review with 49 references describes the electrospinninng (ES process for polysaccharides, cellulose and chitosan, and their derivatives, including cellulose acetate and hydroxypropyl cellulose. A majority of applied studies adopted a two step-process, in which the cellulose acetate was used for the first ES process, followed by acetyl group removal to regenerate cellulose thin fibers. The electrospun nonwoven fabrics (ESNW of regenerated cellulose can be modified by introduction of aldehyde groups by oxidative cleavage of vicinal diols using periodates, and these aldehyde groups serve as acceptors of foreign substances, with various chemical/biological functions, to be immobilized on the fiber surfaces in the ESNW matrices. Direct electrospinning of cellulose from trifluroacetic acid solution was also developed and the applied studies were summarized to conclude the current trends of interests in the ES and related technologies.

  14. Assessing nano cellulose developments using science and technology indicators

    Energy Technology Data Exchange (ETDEWEB)

    Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues, E-mail: douglasmilanez@yahoo.com.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Nucleo de Informacao Tecnologica em Materiais. Dept. de Engenharia de Materiais

    2013-11-01

    This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

  15. Surface engineering of ultrafine cellulose nanofibrils toward polymer nanocomposite materials.

    Science.gov (United States)

    Fujisawa, Shuji; Saito, Tsuguyuki; Kimura, Satoshi; Iwata, Tadahisa; Isogai, Akira

    2013-05-13

    Surface grafting of crystalline and ultrafine cellulose nanofibrils with poly(ethylene glycol) (PEG) chains via ionic bonds was achieved by a simple ion-exchange treatment. The PEG-grafted cellulose nanofibrils exhibited nanodispersibility in organic solvents such as chloroform, toluene, and tetrahydrofuran. Then, the PEG-grafted cellulose nanofibril/chloroform dispersion and poly(L-lactide) (PLLA)/chloroform solution were mixed, and the PEG-grafted cellulose nanofibril/PLLA composite films with various blend ratios were prepared by casting the mixtures on a plate and drying. The tensile strength, Young's modulus, and work of fracture of the composite films were remarkably improved, despite low cellulose addition levels (cellulose nanofibrils in the PLLA matrix. Moreover, some attractive interactions mediated by the PEG chains were likely to be formed between the cellulose nanofibrils and PLLA molecules in the composites, additionally enhancing the efficient nanocomposite effect.

  16. Microfibrillated cellulose as reinforcement for Li-ion battery polymer electrolytes with excellent mechanical stability

    Science.gov (United States)

    Chiappone, A.; Nair, Jijeesh R.; Gerbaldi, C.; Jabbour, L.; Bongiovanni, R.; Zeno, E.; Beneventi, D.; Penazzi, N.

    Methacrylic-based thermo-set gel-polymer electrolyte membranes obtained by a very easy, fast and reliable free radical photo-polymerisation process and reinforced with microfibrillated cellulose particles are here presented. The morphology of the composite electrolytes is investigated by scanning electron microscopy and their thermal behaviour (characteristic temperatures, degradation temperature) are investigated by thermo-gravimetric analysis and differential scanning calorimetry. The composite membranes prepared exhibit excellent mechanical properties, with a Young's modulus as high as about 80 MPa at ambient temperature. High ionic conductivity (approaching 10 -3 S cm -1 at 25 °C) and good overall electrochemical performances are maintained, enlightening that such specific approach would make these hybrid organic, cellulose-based composite polymer electrolyte systems a strong contender in the field of thin and flexible lithium based power sources.

  17. Investigation of the powder flow behaviour of binary mixtures of microcrystalline celluloses and paracetamol

    Directory of Open Access Journals (Sweden)

    Ira Soppela

    2010-03-01

    Full Text Available The flow behaviour of binary mixtures of paracetamol and different grades of microcrystalline celluloses (Avicel® PH101, PH102 and PH200 was studied using a new testing method. The effect of physical characteristics of the powder including tribocharging and the addition of lubricant on the flow properties of the different mixtures was investigated. As expected, the flowability of the samples was affected both by the amount of paracetamol and the physical properties of microcrystalline celluloses (MCC and the mixtures. The effect of lubricant varied depending on the MCC grade: magnesium stearate was able to improve the flowability of the mixtures containing PH102 and PH200 while it did not affect the flowability of PH101. Multivariate analysis showed that the flow of the binary excipient-drug mixtures through an orifice is affected by several phenomena, such as charging, surface moisture, carrier payload and particle size.

  18. Reactor scale up for biological conversion of cellulosic biomass to ethanol.

    Science.gov (United States)

    Shao, Xiongjun; Lynd, Lee; Bakker, André; LaRoche, Richard; Wyman, Charles

    2010-05-01

    The absence of a systematic scale-up approach for biological conversion of cellulosic biomass to commodity products is a significant bottleneck to realizing the potential benefits offered by such conversion. Motivated by this, we undertook to develop a scale-up approach for conversion of waste paper sludge to ethanol. Physical properties of the system were measured and correlations were developed for their dependence upon cellulose conversion. Just-suspension of solid particles was identified as the scale up criterion based on experiments at lab scale. The impeller speed for just solids suspension at large scale was predicted using computational fluid dynamics simulations. The scale-up strategy was validated by analyzing mixing requirements such as solid-liquid mass transfer under the predicted level of agitation at large scale. The scale-up approach enhances the prediction of reactor performance and helps provide guidelines for the analysis and design of large scale bioreactors based on bench scale experimentation.

  19. Enzymatic saccharification of cellulose and cellulosic biomass of sweet potato (Ipomoea batatas L. ): two-step hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, M.E.M.; Bhattacharya, S.; Biswas, P.K.

    1986-01-01

    The enzymatic hydrolysis of lignocellulosic biomass of sweet potato vines as well as microcrystalline cellulose, Sigmacell type 20, by cellulases from Trichoderma viride is reported. Material was treated with a concentrated solution of ZnCl2 and 0.5% hydrochloric acid and heated at 145C for 12 minutes. Hydrolysis of the cellulose precipitated by acetone was 2-2.5 times greater than untreated lignocellulose and approached 64% conversion. A two-step hydrolysis of treated or untreated cellulose resulted in higher conversion of cellulose into reducing sugars. Increasing cellulase concentrations increased the conversion, but an increase in substrate concentration resulted in a decrease in cellulose conversion. 20 references.

  20. Morphology and physical-chemical properties of celluloses obtained by different methods

    Science.gov (United States)

    Anpilova, A. Yu.; Mastalygina, E. E.; Mikhaylov, I. A.; Popov, A. A.; Kartasheva, Z. S.

    2017-12-01

    The morphology and structural characteristics of celluloses obtained by different methods were studied. The objects of the investigation are cellulose from pulp source, commercial celluloses produced by sodium and acid hydrolysis, laboratory produced cellulose from bleached birch kraft pulp, and cellulose obtained by thermooxidative catalytic treatment of maple leaves by peroxide. According to a complex analysis of cellulose characteristics, several types of celluloses were offered as modifying additives for polymers.

  1. Pt nanocatalysts supported on reduced graphene oxide for selective conversion of cellulose or cellobiose to sorbitol.

    Science.gov (United States)

    Wang, Ding; Niu, Wenqi; Tan, Minghui; Wu, Mingbo; Zheng, Xuejun; Li, Yanpeng; Tsubaki, Noritatsu

    2014-05-01

    Pt nanocatalysts loaded on reduced graphene oxide (Pt/RGO) were prepared by means of a convenient microwave-assisted reduction approach with ethylene glycol as reductant. The conversion of cellulose or cellobiose into sorbitol was used as an application reaction to investigate their catalytic performance. Various metal nanocatalysts loaded on RGO were compared and RGO-supported Pt exhibited the highest catalytic activity with 91.5 % of sorbitol yield from cellobiose. The catalytic performances of Pt nanocatalysts supported on different carbon materials or on silica support were also compared. The results showed that RGO was the best catalyst support, and the yield of sorbitol was as high as 91.5 % from cellobiose and 58.9 % from cellulose, respectively. The improvement of catalytic activity was attributed to the appropriate Pt particle size and hydrogen spillover effect of Pt/RGO catalyst. Interestingly, the size and dispersion of supported Pt particles could be easily regulated by convenient adjustment of the microwave heating temperature. The catalytic performance was found to initially increase and then decrease with increasing particle size. The optimum Pt particle size was 3.6 nm. These findings may offer useful guidelines for designing novel catalysts with beneficial catalytic performance for biomass conversion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

    Directory of Open Access Journals (Sweden)

    Elena Vismara

    2013-05-01

    Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

  3. A novel approach to a fine particle coating using porous spherical silica as core particles.

    Science.gov (United States)

    Ishida, Makoto; Uchiyama, Jumpei; Isaji, Keiko; Suzuki, Yuta; Ikematsu, Yasuyuki; Aoki, Shigeru

    2014-08-01

    Abstract The applicability of porous spherical silica (PSS) was evaluated as core particles for pharmaceutical products by comparing it with commercial core particles such as mannitol (NP-108), sucrose and microcrystalline cellulose spheres. We investigated the physical properties of core particles, such as particle size distribution, flow properties, crushing strength, plastic limit, drying rate, hygroscopic property and aggregation degree. It was found that PSS was a core particle of small particle size, low friability, high water adsorption capacity, rapid drying rate and lower occurrence of particle aggregation, although wettability is a factor to be carefully considered. The aggregation and taste-masking ability using PSS and NP-108 as core particles were evaluated at a fluidized-bed coating process. The functional coating under the excess spray rate shows different aggregation trends and dissolution profiles between PSS and NP-108; thereby, exhibiting the formation of uniform coating under the excess spray rate in the case of PSS. This expands the range of the acceptable spray feed rates to coat fine particles, and indicates the possibility of decreasing the coating time. The results obtained in this study suggested that the core particle, which has a property like that of PSS, was useful in overcoming such disadvantages as large particle size, which feels gritty in oral cavity; particle aggregation; and the long coating time of the particle coating process. These results will enable the practical fine particle coating method by increasing the range of optimum coating conditions and decreasing the coating time in fluidized bed technology.

  4. IMPACTS OF BIOFILM FORMATION ON CELLULOSE FERMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Leschine, Susan

    2009-10-31

    This project addressed four major areas of investigation: i) characterization of formation of Cellulomonas uda biofilms on cellulose; ii) characterization of Clostridium phytofermentans biofilm development; colonization of cellulose and its regulation; iii) characterization of Thermobifida fusca biofilm development; colonization of cellulose and its regulation; and iii) description of the architecture of mature C. uda, C. phytofermentans, and T. fusca biofilms. This research is aimed at advancing understanding of biofilm formation and other complex processes involved in the degradation of the abundant cellulosic biomass, and the biology of the microbes involved. Information obtained from these studies is invaluable in the development of practical applications, such as the single-step bioconversion of cellulose-containing residues to fuels and other bioproducts. Our results have clearly shown that cellulose-decomposing microbes rapidly colonize cellulose and form complex structures typical of biofilms. Furthermore, our observations suggest that, as cells multiply on nutritive surfaces during biofilms formation, dramatic cell morphological changes occur. We speculated that morphological changes, which involve a transition from rod-shaped cells to more rounded forms, might be more apparent in a filamentous microbe. In order to test this hypothesis, we included in our research a study of biofilm formation by T. fusca, a thermophilic cellulolytic actinomycete commonly found in compost. The cellulase system of T. fusca has been extensively detailed through the work of David Wilson and colleagues at Cornell, and also, genome sequence of a T. fusca strain has been determine by the DOE Joint Genome Institute. Thus, T. fusca is an excellent subject for studies of biofilm development and its potential impacts on cellulose degradation. We also completed a study of the chitinase system of C. uda. This work provided essential background information for understanding how C. uda

  5. Enzymatic digestion of partially and fully regenerated cellulose model films from trimethylsilyl cellulose.

    Science.gov (United States)

    Mohan, Tamilselvan; Kargl, Rupert; Doliška, Aleš; Ehmann, Heike M A; Ribitsch, Volker; Stana-Kleinschek, Karin

    2013-03-01

    Partially and fully regenerated cellulose model films from trimethylsilyl cellulose (TMSC) were prepared by a time dependent regeneration approach. These thin films were characterized with contact angle measurements and attenuated total reflectance infrared spectroscopy (ATR-IR). In order to get further insights into the completeness of the regeneration we studied the interaction of cellulase enzymes from Trichoderma viride with the cellulose films using a quartz crystal microbalance with dissipation (QCM-D). To support the results from the QCM-D experiments capillary zone electrophoresis (CZE) and atomic force microscopy (AFM) were applied. The changes in mass and energy dissipation due to the interaction of the enzymes with the substrates were correlated with the surface wettability and elemental composition of the regenerated films. The highest interaction activity between the films and the enzyme, as well as the highest cellulose degradation, was observed on fully regenerated cellulose films, but some degradation also occurred on pure TMSC films. The enzymatic degradation rate correlated well with the rate of regeneration. It was demonstrated that CZE can be used to support QCM-D data via the detection of enzyme hydrolysis products in the eluates of the QCM-D cells. Glucose release peaked at the same time as the maximum mass loss was detected via QCM-D. It was shown that a combination of QCM-D and CZE together with enzymatic digestion is a reliable method to determine the conversion rate of TMSC to cellulose. In addition QCM-D and AFM revealed that cellulase is irreversibly bound to hydrophobic TMSC surfaces, while pure cellulose is digested almost completely in the course of hydrolysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Plot of charged nuclear particles in polymers

    International Nuclear Information System (INIS)

    Gallardo H, J.I.L.

    1975-01-01

    Experiments were made in order to obtain particle tracks and fission fragments in polymers. To increase the damage the polymer is attacked chemically with a solution of KOH, NaOH or other chemical agent, whose concentration depends of the polymer to be treated, maintaining a constant temperature during the process. To count the tracks which perforate the film, a spark counter with controlled nitrogen atmosphere was constructed. In the experiments which were made in order to detect particles, films of cellulose nitrate known as xylonite, daicel and red paper were used. For the detection of fission products, cellulose triacetate and cellulose polycarbonate films, known as kodacel and kimfol were used. The particle tracks on the treated films were optically counted with a microscope. They had a diameter between 12 and 30 microns, and when the thickness of the film permitted it the tracks consisted in perforations from one to another side of the film. The obtained results have permitted to have the necessary reproducibility for the realization of quantitative analysis of irradiations which can be applied to neutron dosimetry. (author)

  7. Lignin from hydrothermally pretreated grass biomass retards enzymatic cellulose degradation by acting as a physical barrier rather than by inducing nonproductive adsorption of enzymes

    DEFF Research Database (Denmark)

    Djajadi, Demi T.; Jensen, Mads M.; Oliveira, Marlene

    2018-01-01

    Lignin is known to hinder efficient enzymatic conversion of lignocellulose in biorefining processes. In particular, nonproductive adsorption of cellulases onto lignin is considered a key mechanism to explain how lignin retards enzymatic cellulose conversion in extended reactions. Lignin.......97. The LRRs had different residual carbohydrate levels-the highest in MS; the lowest in WS. The residual carbohydrate was not traceable at the surface of the LRRs particles by ATR-FTIR analysis. The chemical properties of the lignin in the LRRs varied across the three types of biomass, but monolignols...... of the enzymes to the LRRs. Since the surface of the LRRs particles were covered by lignin, the data suggest that the retardation of enzymatic cellulose degradation during extended reaction on lignocellulosic substrates is due to physical blockage of the access of enzymes to the cellulose caused by the gradual...

  8. Derivatization-free gel permeation chromatography elucidates enzymatic cellulose hydrolysis

    Directory of Open Access Journals (Sweden)

    Engel Philip

    2012-10-01

    Full Text Available Abstract Background The analysis of cellulose molecular weight distributions by gel permeation chromatography (GPC is a powerful tool to obtain detailed information on enzymatic cellulose hydrolysis, supporting the development of economically viable biorefinery processes. Unfortunately, due to work and time consuming sample preparation, the measurement of cellulose molecular weight distributions has a limited applicability until now. Results In this work we present a new method to analyze cellulose molecular weight distributions that does not require any prior cellulose swelling, activation, or derivatization. The cellulose samples were directly dissolved in dimethylformamide (DMF containing 10-20% (v/v 1-ethyl-3-methylimidazolium acetate (EMIM Ac for 60 minutes, thereby reducing the sample preparation time from several days to a few hours. The samples were filtrated 0.2 μm to avoid column blocking, separated at 0.5 mL/min using hydrophilic separation media and were detected using differential refractive index/multi angle laser light scattering (dRI/MALLS. The applicability of this method was evaluated for the three cellulose types Avicel, α-cellulose and Sigmacell. Afterwards, this method was used to measure the changes in molecular weight distributions during the enzymatic hydrolysis of the different untreated and ionic liquid pretreated cellulose substrates. The molecular weight distributions showed a stronger shift to smaller molecular weights during enzymatic hydrolysis using a commercial cellulase preparation for cellulose with lower crystallinity. This was even more pronounced for ionic liquid-pretreated cellulose. Conclusions In conclusion, this strongly simplified GPC method for cellulose molecular weight distribution allowed for the first time to demonstrate the influence of cellulose properties and pretreatment on the mode of enzymatic hydrolysis.

  9. Microfibrillated cellulose, a new cellulose product: properties, uses, and commercial potential

    Energy Technology Data Exchange (ETDEWEB)

    Turbak, A.F.; Snyder, F.W.; Sandberg, K.R.

    1983-01-01

    A new form of cellulose, which is expanded to a smooth gel when dispersed in polar liquids, is produced by a unique, rapid, physical treatment of wood cellulose pulps. A 2% suspension of microfibrillated cellulose (MFC) in water has thixotropic viscosity properties and is a stable gel on storage, or when subjected to freeze-thaw cycles. At this concentration, MFC is an excellent suspending medium for other solids and an emulsifying base for organic liquids. In laboratory tests, microfibrillated cellulose has been demonstrated to have wide utility in the preparation of foods such as low-calorie whipped toppings, cake frostings, salad dressings, gravies, and sauces. At 0.3% cellulose concentration in ground meats, MFC helps retain juices during cooking. Tests were also conducted in formulating paints, emulsions, and cosmetics and in the use of MFC as a binder for nonwoven textiles and as a mineral suspending agent. From economic studies, it is estimated that a 2% MFC dispersion can be produced for about 1.5 cents/lb, total cost. 6 references, 9 figures, 2 tables.

  10. Isolation and characterization of cellulose nanowhiskers from oil palm biomass microcrystalline cellulose.

    Science.gov (United States)

    Haafiz, M K Mohamad; Hassan, Azman; Zakaria, Zainoha; Inuwa, I M

    2014-03-15

    The objective of this study is to compare the effect of two different isolation techniques on the physico-chemical and thermal properties of cellulose nanowhiskers (CNW) from oil palm biomass obtained microcrystalline cellulose (MCC). Fourier transform infrared analysis showed that there are no significant changes in the peak positions, suggesting that the treatments did not affect the chemical structure of the cellulose fragment. Scanning electron microscopy showed that the aggregated structure of MCC is broken down after treatment. Transmission electron microscopy revealed that the produced CNW displayed a nanoscale structure. X-ray diffraction analysis indicated that chemical swelling improves the crystallinity of MCC while maintaining the cellulose I structure. Acid hydrolysis however reduced the crystallinity of MCC and displayed the coexistence of cellulose I and II allomorphs. The produced CNW is shown to have a good thermal stability and hence is suitable for a range of applications such as green biodegradable nanocomposites reinforced with CNW. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Interactions between microfibrillar cellulose and carboxymethyl cellulose in an aqueous suspension.

    Science.gov (United States)

    Agarwal, Deepa; MacNaughtan, William; Foster, Tim J

    2018-04-01

    New microstructures with interesting, unique and stable textures, particularly relevant to food systems were created by redispersing Microfibrillar cellulose (MFC). This paper reports the interactions between microfibrillar cellulose and carboxymethyl cellulose (CMC) in redispersed aqueous suspensions, by using rheological measurements on variable ratios of MFC/CMC and correlating these with apparent water mobility as determined by time domain NMR. MFC is a network of cellulose fibrils produced by subjecting pure cellulose pulp to high-pressure mechanical homogenisation. A charged polymer such as CMC reduces the aggregation of microfibrillar/fibre bundles upon drying. Small amplitude oscillatory rheological analysis showed viscoelastic gel-like behaviour of suspensions which was independent of the CMC content in the MFC suspension. A viscous synergistic effect was observed when CMC was added to MFC before drying, leading to improved redispersibility of the suspension. Novel measurements using NMR relaxation suggested that the aggregated microfibrillar/fibre bundles normally dominate the relaxation times (T 2 ). The dense microfibrillar network plays an important role in generating stable rheological properties and controlling the mobility of the polymer and hence the apparent mobility of the water in the suspensions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Using carboxylated nanocrystalline cellulose as an additive in cellulosic paper and poly (vinyl alcohol) fiber paper.

    Science.gov (United States)

    Cha, Ruitao; Wang, Chengyu; Cheng, Shaoling; He, Zhibin; Jiang, Xingyu

    2014-09-22

    Specialty paper (e.g. cigarette paper and battery diaphragm paper) requires extremely high strength properties. The addition of strength agents plays an important role in increasing strength properties of paper. Nanocrystalline cellulose (NCC), or cellulose whiskers, has the potential to enhance the strength properties of paper via improving inter-fibers bonding. This paper was to determine the potential of using carboxylated nanocrystalline cellulose (CNCC) to improve the strength properties of paper made of cellulosic fiber or poly (vinyl alcohol) (PVA) fiber. The results indicated that the addition of CNCC can effectively improve the strength properties. At a CNCC dosage of 0.7%, the tear index and tensile index of the cellulosic paper reached the maximum of 12.8 mN m2/g and 100.7 Nm/g, respectively. More importantly, when increasing the CNCC dosage from 0.1 to 1.0%, the tear index and tensile index of PVA fiber paper were increased by 67.29%, 22.55%, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Reinforced plastics and aerogels by nanocrystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Alfred C. W.; Lam, Edmond; Chong, Jonathan; Hrapovic, Sabahudin; Luong, John H. T., E-mail: john.luong@cnrc-nrc.gc.ca [National Research Council Canada (Canada)

    2013-05-15

    Nanocrystalline cellulose (NCC), a rigid rod-like nanoscale material, can be produced from cellulosic biomass in powder, liquid, or gel forms by acid and chemical hydrolysis. Owing to its unique and exceptional physicochemical properties, the incorporation of a small amount of NCC into plastic enhances the mechanical strength of the latter by several orders of magnitudes. Carbohydrate-based NCC poses no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites and aerogels. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic or hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement effect.

  14. Microbial mineralization of cellulose in frozen soils.

    Science.gov (United States)

    Segura, Javier H; Nilsson, Mats B; Haei, Mahsa; Sparrman, Tobias; Mikkola, Jyri-Pekka; Gräsvik, John; Schleucher, Jürgen; Öquist, Mats G

    2017-10-27

    High-latitude soils store ~40% of the global soil carbon and experience winters of up to 6 months or more. The winter soil CO 2 efflux importantly contributes to the annual CO 2 budget. Microorganisms can metabolize short chain carbon compounds in frozen soils. However, soil organic matter (SOM) is dominated by biopolymers, requiring exoenzymatic hydrolysis prior to mineralization. For winter SOM decomposition to have a substantial influence on soil carbon balances it is crucial whether or not biopolymers can be metabolized in frozen soils. We added 13 C-labeled cellulose to frozen (-4 °C) mesocosms of boreal forest soil and followed its decomposition. Here we show that cellulose biopolymers are hydrolyzed under frozen conditions sustaining both CO 2 production and microbial growth contributing to slow, but persistent, SOM mineralization. Given the long periods with frozen soils at high latitudes these findings are essential for understanding the contribution from winter to the global carbon balance.

  15. Retention of Cationic Starch onto Cellulose Fibres

    Science.gov (United States)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  16. Biosorbents prepared from wood particles treated with anionic polymer and iron salt: Effect of particle size on phosphate adsorption

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min

    2008-01-01

    Biomass-based adsorbents have been widely studied as a cost-effective and environmentally-benign means to remove pollutants and nutrients from water. A two-stage treatment of aspen wood particles with solutions of carboxymethyl cellulose (CMC) and ferrous chloride afforded a biosorbent that was effective in removing phosphate from test solutions. FTIR spectroscopy of...

  17. Ultrasound-assisted dyeing of cellulose acetate.

    Science.gov (United States)

    Udrescu, C; Ferrero, F; Periolatto, M

    2014-07-01

    The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with Disperse Red 50 using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or coupling mechanical and ultrasound agitation in the bath where the temperature range was maintained between 60 and 80 °C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries (90% of bath exhaustion value at 80 °C). Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound added to mechanical agitation was evidenced by the lower value (48 kJ/mol) in comparison with 112 and 169 kJ/mol for mechanical stirring alone with auxiliaries and without, respectively. Finally, the fastness tests gave good values for samples dyed with ultrasound technique even without auxiliaries. Moreover color measurements on dyed yarns showed that the color yield obtained by ultrasound-assisted dyeing at 80 °C of cellulose acetate without using additional chemicals into the dye bath reached the same value yielded by mechanical agitation, but with remarkably shorter time. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Cellulose conversion of corn pericarp without pretreatment.

    Science.gov (United States)

    Kim, Daehwan; Orrego, David; Ximenes, Eduardo A; Ladisch, Michael R

    2017-12-01

    We report enzyme hydrolysis of cellulose in unpretreated pericarp at a cellulase loading of 0.25FPU/g pericarp solids using a phenol tolerant Aspergillus niger pectinase preparation. The overall protein added was 5mg/g and gave 98% cellulose conversion in 72h. However, for double the amount of enzyme from Trichoderma reesei, which is significantly less tolerant to phenols, conversion was only 16%. The key to achieving high conversion without pretreatment is combining phenol inhibition-resistant enzymes (such as from A. niger) with unground pericarp from which release of phenols is minimal. Size reduction of the pericarp, which is typically carried out in a corn-to-ethanol process, where corn is first ground to a fine powder, causes release of highly inhibitory phenols that interfere with cellulase enzyme activity. This work demonstrates hydrolysis without pretreatment of large particulate pericarp is a viable pathway for directly producing cellulose ethanol in corn ethanol plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Quantifying Supply Risk at a Cellulosic Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Jason K [Idaho National Laboratory; Jacobson, Jacob Jordan [Idaho National Laboratory; Cafferty, Kara Grace [Idaho National Laboratory; Lamers, Patrick [Idaho National Laboratory; Roni, MD S [Idaho National Laboratory

    2015-03-01

    In order to increase the sustainability and security of the nation’s energy supply, the U.S. Department of Energy through its Bioenergy Technology Office has set a vision for one billion tons of biomass to be processed for renewable energy and bioproducts annually by the year 2030. The Renewable Fuels Standard limits the amount of corn grain that can be used in ethanol conversion sold in the U.S, which is already at its maximum. Therefore making the DOE’s vision a reality requires significant growth in the advanced biofuels industry where currently three cellulosic biorefineries convert cellulosic biomass to ethanol. Risk mitigation is central to growing the industry beyond its infancy to a level necessary to achieve the DOE vision. This paper focuses on reducing the supply risk that faces a firm that owns a cellulosic biorefinery. It uses risk theory and simulation modeling to build a risk assessment model based on causal relationships of underlying, uncertain, supply driving variables. Using the model the paper quantifies supply risk reduction achieved by converting the supply chain from a conventional supply system (bales and trucks) to an advanced supply system (depots, pellets, and trains). Results imply that the advanced supply system reduces supply system risk, defined as the probability of a unit cost overrun, from 83% in the conventional system to 4% in the advanced system. Reducing cost risk in this nascent industry improves the odds of realizing desired growth.

  20. Quantifying Supply Risk at a Cellulosic Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Jason K.; Jacobson, Jacob J.; Cafferty, Kara G.; Lamers, Patrick; Roni, Mohammad S.

    2015-07-01

    In order to increase the sustainability and security of the nation’s energy supply, the U.S. Department of Energy through its Bioenergy Technology Office has set a vision for one billion tons of biomass to be processed for renewable energy and bioproducts annually by the year 2030. The Renewable Fuels Standard limits the amount of corn grain that can be used in ethanol conversion sold in the U.S, which is already at its maximum. Therefore making the DOE’s vision a reality requires significant growth in the advanced biofuels industry where currently three cellulosic biorefineries convert cellulosic biomass to ethanol. Risk mitigation is central to growing the industry beyond its infancy to a level necessary to achieve the DOE vision. This paper focuses on reducing the supply risk that faces a firm that owns a cellulosic biorefinery. It uses risk theory and simulation modeling to build a risk assessment model based on causal relationships of underlying, uncertain, supply driving variables. Using the model the paper quantifies supply risk reduction achieved by converting the supply chain from a conventional supply system (bales and trucks) to an advanced supply system (depots, pellets, and trains). Results imply that the advanced supply system reduces supply system risk, defined as the probability of a unit cost overrun, from 83% in the conventional system to 4% in the advanced system. Reducing cost risk in this nascent industry improves the odds of realizing desired growth.

  1. Cellulose pulp produced from bulrush fiber

    Directory of Open Access Journals (Sweden)

    Vania Karine Dick Wille

    Full Text Available ABSTRACT: Brazil continues to use wood as the principal raw material source for the pulp industry; although, non-wood fibers have been revealed to be a competent substitute to produce paper with different and exceptional properties. Keeping this in focus, this study aimed to assess potential of Schoenoplectus californicus fibers (C. A. Mey. Soják, commonly identified as bulrush or reed, in cellulosic pulp generation, as an alternative fiber source for the pulp and paper industry. On analyzing the chemical composition of reed fibers, extractives of lignin, carbohydrates, uronic acids and minerals were reported. Physico-chemical characteristics of reed-based cellulosic pulp were estimated including viscosity, hexenuronic acids, etc., as well as anatomical features of length, width, etc. From the chemical analyses of the reed the presence of high concentrations of extractives and silica was clear, making them unfit as raw material for cellulosic pulp production. Pulp kraft pulping process produced brown pulps low in viscosity (34.5m Pa.s and hexenuronic acid content. Reed is thus classifiable as short-fiber source for pulp and paper industries.

  2. Cosmic particles

    International Nuclear Information System (INIS)

    Fritszh, Harald; Max-Planck-Institut fuer Physik und Astrophysik, Muenchen

    1986-01-01

    The paper on 'Cosmic particles' was presented at the conference on 'The early universe and its evolution', Erice, Italy 1986. The link between ideas in cosmology and in elementary particle physics is examined. The subject is discussed under the following topic headings: cosmic kinetics, cosmic dynamics and general relativity, dynamics of the dust universe, particle physics, unity of quarks and leptons, the hot universe and standard particle physics, creation of matter, and the inflation of the universe. (U.K.)

  3. High pressure HC1 conversion of cellulose to glucose

    Energy Technology Data Exchange (ETDEWEB)

    Antonoplis, Robert Alexander [Univ. of California, Berkeley, CA (United States); Blanch, Harvey W. [Univ. of California, Berkeley, CA (United States); Wilke, Charles R. [Univ. of California, Berkeley, CA (United States)

    1981-08-01

    The production of ethanol from glucose by means of fermentation represents a potential long-range alternative to oil for use as a transportation fuel. Today's rising oil prices and the dwindling world supply of oil have made other fuels, such as ethanol, attractive alternatives. It has been shown that automobiles can operate, with minor alterations, on a 10% ethanol-gasoline mixture popularly known as gasohol. Wood has long been known as a potential source of glucose. Glucose may be obtained from wood following acid hydrolysis. In this research, it was found that saturating wood particles with HCl gas under pressure was an effective pretreatment before subjecting the wood to dilute acid hydrolysis. The pretreatment is necessary because of the tight lattice structure of cellulose, which inhibits dilute acid hydrolysis. HCl gas makes the cellulose more susceptible to hydrolysis and the glucose yield is doubled when dilute acid hydrolysis is preceded by HCl saturation at high pressure. The saturation was most effectively performed in a fluidized bed reactor, with pure HCl gas fluidizing equal volumes of ground wood and inert particles. The fluidized bed effectively dissipated the large amount of heat released upon HCl absorption into the wood. Batch reaction times of one hour at 314.7 p.s.i.a. gave glucose yields of 80% and xylose yields of 95% after dilute acid hydrolysis. A non-catalytic gas-solid reaction model, with gas diffusing through the solid limiting the reaction rate, was found to describe the HCl-wood reaction in the fluidized bed. HCl was found to form a stable adduct with the lignin residue in the wood, in a ratio of 3.33 moles per mole of lignin monomer. This resulted in a loss of 0.1453 lb. of HCl per pound of wood. The adduct was broken upon the addition of water. A process design and economic evaluation for a plant to produce 214 tons per day of glucose from air-dried ground Populus tristi gave an estimated glucose cost of 15.14 cents per pound

  4. Strange particles

    International Nuclear Information System (INIS)

    Chinowsky, W.

    1989-01-01

    Work done in the mid 1950s at Brookhaven National Laboratory on strange particles is described. Experiments were done on the Cosmotron. The author describes his own and others' work on neutral kaons, lambda and theta particles and points out the theoretical gap between predictions and experimental findings. By the end of the decade, the theory of strange particles was better understood. (UK)

  5. Traffic jams reduce hydrolytic efficiency of cellulase on cellulose surface.

    Science.gov (United States)

    Igarashi, Kiyohiko; Uchihashi, Takayuki; Koivula, Anu; Wada, Masahisa; Kimura, Satoshi; Okamoto, Tetsuaki; Penttilä, Merja; Ando, Toshio; Samejima, Masahiro

    2011-09-02

    A deeper mechanistic understanding of the saccharification of cellulosic biomass could enhance the efficiency of biofuels development. We report here the real-time visualization of crystalline cellulose degradation by individual cellulase enzymes through use of an advanced version of high-speed atomic force microscopy. Trichoderma reesei cellobiohydrolase I (TrCel7A) molecules were observed to slide unidirectionally along the crystalline cellulose surface but at one point exhibited collective halting analogous to a traffic jam. Changing the crystalline polymorphic form of cellulose by means of an ammonia treatment increased the apparent number of accessible lanes on the crystalline surface and consequently the number of moving cellulase molecules. Treatment of this bulky crystalline cellulose simultaneously or separately with T. reesei cellobiohydrolase II (TrCel6A) resulted in a remarkable increase in the proportion of mobile enzyme molecules on the surface. Cellulose was completely degraded by the synergistic action between the two enzymes.

  6. Biocomposite cellulose-alginate films: promising packaging materials.

    Science.gov (United States)

    Sirviö, Juho Antti; Kolehmainen, Aleksi; Liimatainen, Henrikki; Niinimäki, Jouko; Hormi, Osmo E O

    2014-05-15

    Biocomposite films based on cellulose and alginate were produced using unmodified birch pulp, microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC) and birch pulp derivate, nanofibrillated anionic dicarboxylic acid cellulose (DCC), having widths of fibres ranging from 19.0 μm to 25 nm as cellulose fibre materials. Ionically cross-linked biocomposites were produced using Ca(2+) cross-linking. Addition of micro- and nanocelluloses as a reinforcement increased the mechanical properties of the alginate films remarkably, e.g. addition of 15% of NFC increased a tensile strength of the film from 70.02 to 97.97 MPa. After ionic cross-linking, the tensile strength of the film containing 10% of DCC was increased from 69.63 to 125.31 MPa. The biocomposite films showed excellent grease barrier properties and reduced water vapour permeability (WVP) after the addition of cellulose fibres, except when unmodified birch pulp was used. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Enzymatic hydrolysis of biomimetic bacterial cellulose-hemicellulose composites.

    Science.gov (United States)

    Penttilä, Paavo A; Imai, Tomoya; Hemming, Jarl; Willför, Stefan; Sugiyama, Junji

    2018-06-15

    The production of biofuels and other chemicals from lignocellulosic biomass is limited by the inefficiency of enzymatic hydrolysis. Here a biomimetic composite material consisting of bacterial cellulose and wood-based hemicelluloses was used to study the effects of hemicelluloses on the enzymatic hydrolysis with a commercial cellulase mixture. Bacterial cellulose synthesized in the presence of hemicelluloses, especially xylan, was found to be more susceptible to enzymatic hydrolysis than hemicellulose-free bacterial cellulose. The reason for the easier hydrolysis could be related to the nanoscale structure of the substrate, particularly the packing of cellulose microfibrils into ribbons or bundles. In addition, small-angle X-ray scattering was used to show that the average nanoscale morphology of bacterial cellulose remained unchanged during the enzymatic hydrolysis. The reported easier enzymatic hydrolysis of bacterial cellulose produced in the presence of wood-based xylan offers new insights to overcome biomass recalcitrance through genetic engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Metallization of bacterial cellulose for electrical and electronic device manufacture

    Science.gov (United States)

    Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN; Jansen, Valerie Malyvanh [Memphis, TN; Woodward, Jonathan [Knoxville, TN

    2010-09-28

    A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a metal comprises placing a bacterial cellulose matrix in a solution of a metal salt such that the metal salt is reduced to metallic form and the metal precipitates in or on the matrix. The method for the construction of a fuel cell comprises placing a hydrated bacterial cellulose support structure in a solution of a metal salt such that the metal precipitates in or on the support structure, inserting contact wires into two pieces of the metal impregnated support structure, placing the two pieces of metal impregnated support structure on opposite sides of a layer of hydrated bacterial cellulose, and dehydrating the three layer structure to create a fuel cell.

  9. A xylanase-aided enzymatic pretreatment facilitates cellulose nanofibrillation.

    Science.gov (United States)

    Long, Lingfeng; Tian, Dong; Hu, Jinguang; Wang, Fei; Saddler, Jack

    2017-11-01

    Although biological pretreatment of cellulosic fiber based on endoglucanases has shown some promise to facilitate cellulose nanofibrillation, its efficacy is still limited. In this study, a xylanase-aided endoglucanase pretreatment was assessed on the bleached hardwood and softwood Kraft pulps to facilitate the downstream cellulose nanofibrillation. Four commercial xylanase preparations were compared and the changes of major fiber physicochemical characteristics such as cellulose/hemicellulose content, gross fiber properties, fiber morphologies, cellulose accessibility/degree of polymerization (DP)/crystallinity were systematically evaluated before and after enzymatic pretreatment. It showed that the synergistic cooperation between endoglucanase and certain xylanase (Biobrite) could efficiently "open up" the hardwood Kraft pulp with limited carbohydrates degradation (cellulose nanofibrillation during mild sonication process (90Wh) with more uniform disintegrated nanofibril products (50-150nm, as assessed by scanning electron microscopy and UV-vis spectroscopy). Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Adsorption of phospholipid bilayers onto pullulan-modified cellulose surfaces

    Science.gov (United States)

    Choi, Heejun; Liu, Zelin; Esker, Alan

    2009-03-01

    1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) vesicle adsorption onto regenerated cellulose and pullulan 4-bromocinnamate (P4BC) modified cellulose surfaces was investigated via surface plasmon resonance (SPR) spectroscopy and quartz crystal microbalance with dissipation monitoring (QCM-D). P4BC with a degree of substitution (DS) of 0.061 ± 0.002 from UV measurements and 0.058 from ^1H NMR was synthesized from pullulan and 4-bromocinnamic acid to yield P4BC. The deduced thicknesses from SPR for DMPC layers were ˜3.7 nm (bilayer) on regenerated cellulose surfaces and ˜2.1 nm (monolayer) on P4BC modified cellulose surfaces. Qualitative analysis of the QCM-D data also indicated that the DMPC layers on P4BC modified cellulose surfaces were thinner than on regenerated cellulose surfaces.

  11. Cellulose-Based Bio- and Nanocomposites: A Review

    Directory of Open Access Journals (Sweden)

    Susheel Kalia

    2011-01-01

    Full Text Available Cellulose macro- and nanofibers have gained increasing attention due to the high strength and stiffness, biodegradability and renewability, and their production and application in development of composites. Application of cellulose nanofibers for the development of composites is a relatively new research area. Cellulose macro- and nanofibers can be used as reinforcement in composite materials because of enhanced mechanical, thermal, and biodegradation properties of composites. Cellulose fibers are hydrophilic in nature, so it becomes necessary to increase their surface roughness for the development of composites with enhanced properties. In the present paper, we have reviewed the surface modification of cellulose fibers by various methods. Processing methods, properties, and various applications of nanocellulose and cellulosic composites are also discussed in this paper.

  12. Hydrophobization and smoothing of cellulose nanofibril films by cellulose ester coatings.

    Science.gov (United States)

    Willberg-Keyriläinen, Pia; Vartiainen, Jari; Pelto, Jani; Ropponen, Jarmo

    2017-08-15

    The Cellulose nanofibrils (CNF), also referred to as nanocellulose, is one of the most studied bio-based material in recent year, which has good potential in the future for packaging applications due to its excellent mechanical strength and oxygen barrier properties. In the future, CNF films may also find new applications for example in printed electronics, if the surface smoothness of CNF films can be improved. One way to improve surface smoothness is to use thin coating solutions with zero porosity, such as molar mass controlled cellulose ester coatings. In this study, we have coated CNF films using molar mass controlled cellulose esters with different side chain lengths forming 3-layer film (ester-CNF-ester). These coatings improved significantly the smoothness of CNF films. The 3-layer films have also good water vapor barrier and mechanical properties and the films are heat-sealable, which enable various new applications in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. USE CELLULOSE FOR CLEANING CONCENTRATED SUGAR SOLUTIONS

    Directory of Open Access Journals (Sweden)

    N. G. Kul’neva

    2015-01-01

    Full Text Available Summary. Producing high quality intermediate products in the boiling-crystallization station is an actual problem of sugar production. In the production of white sugar brown sugar syrup is not further purified that decreases the quality of the end product. Studies have been conducted using cellulose as an adsorbent for the purification of concentrated sugar solutions, having affinity to dyes and other impurities. Research have been carried out with the intermediate products of the Lebedyan sugar plant. Test results have shown cellulose ability to adsorb the dyes in sugar production. The influence of the adsorbent concentration and the mass fraction of solids in the syrup on the decolorization effect has been studied; rational process parameters have been obtained. It has been found that proceeding an additional adsorption purification of brown sugars syrup allows to reduce the solution color, increase the amount and quality of the end product. Adsorbing means, received from production wastes on the basis of organic resources, have many advantages: economical, environmentally friendly for disposal, safe to use, reliable and efficient in use. Conducted research on using cellulose as adsorbent for treatment of concentrated sugar solutions, having an affinity for colouring matter and other impurities. The experiments were carried out on the intermediates Lebedyanskiy sugar factory. The test results showed the ability of cellulose to adsorb coloring matter of sugar production. To evaluate the effect of bleaching depending on the mass fraction of dry substances prepared yellow juice filtration of sugar concentration of 55, 60, 65 % with subsequent adsorption purification of cellulose. The results of the experiment built adsorption isotherm of dyestuffs. The influence of the concentration of the adsorbent and a mass fraction of solids of juice filtration on the efficiency of decolorization obtained by rational parameters of the process. It is

  14. Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase.

    Science.gov (United States)

    Cho, Sung Hyun; Purushotham, Pallinti; Fang, Chao; Maranas, Cassandra; Díaz-Moreno, Sara M; Bulone, Vincent; Zimmer, Jochen; Kumar, Manish; Nixon, B Tracy

    2017-09-01

    Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins. © 2017 American Society of Plant Biologists. All Rights Reserved.

  15. Modification of nanofibrillated cellulose with stimuli-responsive polymers

    OpenAIRE

    Cobo Sanchez, Carmen

    2012-01-01

    Research of new sustainable and low cost materials, such as cellulose, is of high interest. Modifications of the cellulose can be performed in order to create a “smart” material which responds to external stimuli, such as variations in pH and temperature, by changing its properties. This “smart” behavior is observed in some polymers, however, for certain applications they exhibit poor mechanical properties. These polymers can be bound by physical adsorption to cellulose, both in macro and nan...

  16. Sustainable green composites of thermoplastic starch and cellulose fibers

    OpenAIRE

    Amnuay Wattanakornsiri; Sampan Tongnunui

    2014-01-01

    Green composites have gained renewed interest as environmental friendly materials and as biodegradable renewable resources for a sustainable development. This review provides an overview of recent advances in green composites based on thermoplastic starch (TPS) and cellulose fibers. It includes information about compositions, preparations, and properties of starch, cellulose fibers, TPS, and green composites based on TPS and cellulose fibers. Introduction and production of these r...

  17. Cellulose contents of some abundant Indian seaweed species.

    Science.gov (United States)

    Siddhanta, Arup K; Kumar, Sanjay; Mehta, Gaurav K; Chhatbar, Mahesh U; Oza, Mihir D; Sanandiya, Naresh D; Chejara, Dharmesh R; Godiya, Chirag B; Kondaveeti, Stalin

    2013-04-01

    Crude cellulose as well as alpha- and beta-celluloses were estimated in thirty-four seaweed species of fifteen orders of Chlorophyta, Phaeophyta and Rhodophyta of Indian waters. The greatest yields of crude cellulose and a-cellulose were obtained from Chaetomorpha aerea (approx. 20.0% and 18.5%, respectively), and of beta-cellulose (approx. 3.1%) from Caulerpa imbricata. The lowest crude cellulose, and alpha-and beta-contents were recorded for the calcareous red alga Liagora indica (approx. 0.90%, 0.70% and 0.10%, respectively). There was little variation in cellulose content among the brown algae, while wide variations in the yields were found in the green and red algae. The present work contributes to the repertoire of 67 Indian seaweed species studied to now for their cellulose contents in our laboratory. The combined studies highlight that Chaetomorpha aerea, Acrosiphonia orientalis, Caulerpa taxifolia, Sargassum tenerrimum, Hydroclathrus clathratus and Gelidiella acerosa possess relatively high (> 10%) cellulose contents, which could be of potential utility.

  18. Wetting kinetics of oil mixtures on fluorinated model cellulose surfaces.

    Science.gov (United States)

    Aulin, Christian; Shchukarev, Andrei; Lindqvist, Josefina; Malmström, Eva; Wågberg, Lars; Lindström, Tom

    2008-01-15

    The wetting of two different model cellulose surfaces has been studied; a regenerated cellulose (RG) surface prepared by spin-coating, and a novel multilayer film of poly(ethyleneimine) and a carboxymethylated microfibrillated cellulose (MFC). The cellulose films were characterized in detail using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM indicates smooth and continuous films on a nanometer scale and the RMS roughness of the RG cellulose and MFC surfaces was determined to be 3 and 6 nm, respectively. The cellulose films were modified by coating with various amounts of an anionic fluorosurfactant, perfluorooctadecanoic acid, or covalently modified with pentadecafluorooctanyl chloride. The fluorinated cellulose films were used to follow the spreading mechanisms of three different oil mixtures. The viscosity and surface tension of the oils were found to be essential parameters governing the spreading kinetics on these surfaces. XPS and dispersive surface energy measurements were made on the cellulose films coated with perfluorooctadecanoic acid. A strong correlation was found between the surface concentration of fluorine, the dispersive surface energy and the contact angle of castor oil on the surface. A dispersive surface energy less than 18 mN/m was required in order for the cellulose surface to be non-wetting (theta e>90 degrees ) by castor oil.

  19. Effect of Water on Cellulose - EMIM Ac - DMSO Solution

    Science.gov (United States)

    Zhang, Xin; Mao, Yimin; Henderson, Doug; Briber, R. M.; Wang, Howard

    Mixtures of ionic liquids (IL) and polar aprotic solvents are found to be effective for dissolving cellulose to form a molecular solution. Cellulose is naturally hygroscopic and water is generally detrimental to the processing of cellulose using ionic liquids. It is important to understand the role of water in the dissolution and processing of cellulose. The effect of water on the dissolution process of cellulose in the solvent mixture - DMSO - 1-Ethyl-3-methylimidazolium acetate (EMIM Ac) has been examined by polarized microscopy, small angle neutron scattering (SANS), small angle X-ray scattering (SAXS) and cloud point measurements. It was found that the presence of small amounts of water led to clustering of cellulose that could be disrupted by increasing temperature. However at high cellulose concentration, addition of water can facilitate the formation clear solutions and gels. Liquid crystalline behavior was observed in solutions with 1%wt of water and 20 %wt of cellulose. A structural repeat distance around 1.2 nm has been observed by SAXS, presumably from the alignment of cellulose chains. Phase diagrams of the solutions will also be presented.

  20. Graft Copolymerization Of Methyl Methacrylate Onto Agave Cellulose

    International Nuclear Information System (INIS)

    Noor Afizah Rosli; Ishak Ahmad; Ibrahim Abdullah; Farah Hannan Anuar

    2014-01-01

    The grafting polymerization of methyl methacrylate (MMA) and Agave cellulose was prepared and the grafting reaction conditions were optimized by varying the reaction time and temperature, and ratio of monomer to cellulose. The resulting graft copolymers were characterized by Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy (SEM). The experimental results showed that the optimal conditions were at a temperature of 45 degree Celsius for 90 min with ratio monomer to cellulose at 1:1 (g/ g). An additional peak at 1738 cm -1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted cellulose, respectively. Grafting of MMA onto cellulose enhanced its thermal stability and SEM observation further furnished evidence of grafting MMA onto Agave cellulose with increasing cellulose diameter and surface roughness. (author)

  1. Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

    DEFF Research Database (Denmark)

    Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

    2011-01-01

    A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

  2. Investigation of Waste Paper Cellulosic Fibers Utilization into Cement Based Building Materials

    Directory of Open Access Journals (Sweden)

    Viola Hospodarova

    2018-03-01

    Full Text Available Recently, the utilization of renewable natural cellulosic materials, such as wood, plants, and waste paper in the preparation of building materials has attracted significant interest. This is due to their advantageous properties, low environmental impact and low cost. The objective of this paper is to investigate the influence of recycled cellulosic fibers (in the amount 0.5 wt % of the filler and binder weight and superplasticizer (in the amount 0.5 wt % of the cement weight on the resulting properties of cement composites (consistency of fresh mixture, density, thermal conductivity, and compressive and flexural strength for hardening times of 1, 3, 7, 28, and 90 days. Plasticizer use improved the workability of fresh cement mixture. In comparison to the reference sample, the results revealed a decrease in density of 6.8% and in the thermal conductivity of composites with cellulosic fibers of 34%. The highest values of compressive (48.4 MPa and flexural (up to 7 MPa strength were achieved for hardened fiber cement specimens with plasticizer due to their significantly better dispersion of cement particles and improved bond strength between fibers and matrix.

  3. Synthesis, Antibacterial and Thermal Studies of Cellulose Nanocrystal Stabilized ZnO-Ag Heterostructure Nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohd Zobir Hussein

    2013-05-01

    Full Text Available Synthesis of ZnO-Ag heterostructure nanoparticles was carried out by a precipitation method with cellulose nanocrystals (CNCs as a stabilizer for antimicrobial and thermal studies. ZnO-Ag nanoparticles were obtained from various weight percentages of added AgNO3 relative to Zn precursors for evaluating the best composition with enhanced functional properties. The ZnO-Ag/CNCs samples were characterized systematically by TEM, XRD, UV, TGA and DTG. From the TEM studies we observed that ZnO-Ag heterostructure nanoparticles have spherical shapes with size diameters in a 9–35 nm range. The antibacterial activities of samples were assessed against the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The CNC-stabilized ZnO-Ag exhibited greater bactericidal activity compared to cellulose-free ZnO-Ag heterostructure nanoparticles of the same particle size. The incorporation of ZnO-Ag hetreostructure nanoparticles significantly increased the thermal stability of cellulose nanocrystals.

  4. Steric stabilization of "charge-free" cellulose nanowhiskers by grafting of poly(ethylene glycol).

    Science.gov (United States)

    Araki, Jun; Mishima, Shiho

    2014-12-24

    A sterically stabilized aqueous suspension of "charge-free" cellulose nanowhiskers was prepared by hydrochloric acid hydrolysis of cotton powders and subsequent surface grafting of monomethoxy poly(ethylene glycol) (mPEG). The preparation scheme included carboxylation of the terminal hydroxyl groups in mPEG via oxidation with silica gel particles carrying 2,2,6,6-tetramethyl-1-pyperidinyloxyl (TEMPO) moieties and subsequent esterification between terminal carboxyls in mPEG and surface hydroxyl groups of cellulose nanowhiskers, mediated by 1,1'-carbonyldiimidazole (CDI) in dimethyl sulfoxide or dimethylacetamide. Some of the prepared PEG-grafted samples showed remarkable flow birefringence and enhanced stability after 24 h, even in 0.1 M NaCl, suggesting successful steric stabilization by efficient mPEG grafting. Actual PEG grafting via ester linkages was confirmed by attenuated total reflectance-Fourier transform infrared spectrometry. In a typical example, the amount of grafted mPEG was estimated as ca. 0.3 g/g cellulose by two measurements, i.e., weight increase after grafting and weight loss after alkali cleavage of ester linkages. Transmission electron microscopy indicated unchanged nanowhisker morphology after mPEG grafting.

  5. Steric Stabilization of “Charge-Free” Cellulose Nanowhiskers by Grafting of Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Jun Araki

    2014-12-01

    Full Text Available A sterically stabilized aqueous suspension of “charge-free” cellulose nanowhiskers was prepared by hydrochloric acid hydrolysis of cotton powders and subsequent surface grafting of monomethoxy poly(ethylene glycol (mPEG. The preparation scheme included carboxylation of the terminal hydroxyl groups in mPEG via oxidation with silica gel particles carrying 2,2,6,6-tetramethyl-1-pyperidinyloxyl (TEMPO moieties and subsequent esterification between terminal carboxyls in mPEG and surface hydroxyl groups of cellulose nanowhiskers, mediated by 1,1'-carbonyldiimidazole (CDI in dimethyl sulfoxide or dimethylacetamide. Some of the prepared PEG-grafted samples showed remarkable flow birefringence and enhanced stability after 24 h, even in 0.1 M NaCl, suggesting successful steric stabilization by efficient mPEG grafting. Actual PEG grafting via ester linkages was confirmed by attenuated total reflectance-Fourier transform infrared spectrometry. In a typical example, the amount of grafted mPEG was estimated as ca. 0.3 g/g cellulose by two measurements, i.e., weight increase after grafting and weight loss after alkali cleavage of ester linkages. Transmission electron microscopy indicated unchanged nanowhisker morphology after mPEG grafting.

  6. Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

    Science.gov (United States)

    Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

    2016-01-01

    Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

  7. Sustained Release of Amoxicillin from Ethyl Cellulose-Coated Amoxicillin/Chitosan–Cyclodextrin-Based Tablets

    OpenAIRE

    Songsurang, Kultida; Pakdeebumrung, Jatuporn; Praphairaksit, Narong; Muangsin, Nongnuj

    2010-01-01

    Sustained release mucoadhesive amoxicillin tablets with tolerance to acid degradation in the stomach were studied. The sustained-release tablets of amoxicillin were prepared from amoxicillin coated with ethyl cellulose (EC) and then formulated into tablets using chitosan (CS) or a mixture of CS and beta-cyclodextrin (CD) as the retard polymer. The effects of various (w/w) ratios of EC/amoxicillin, the particle sized of EC coated amoxicillin and the different (w/w) ratios of CS/CD for the reta...

  8. Characterization of genes in the cellulose-synthesizing operon (acs operon) of Acetobacter xylinum: implications for cellulose crystallization.

    OpenAIRE

    Saxena, I M; Kudlicka, K; Okuda, K; Brown, R M

    1994-01-01

    The synthesis of an extracellular ribbon of cellulose in the bacterium Acetobacter xylinum takes place from linearly arranged, membrane-localized, cellulose-synthesizing and extrusion complexes that direct the coupled steps of polymerization and crystallization. To identify the different components involved in this process, we isolated an Acetobacter cellulose-synthesizing (acs) operon from this bacterium. Analysis of DNA sequence shows the presence of three genes in the acs operon, in which ...

  9. Regiocontroll synthesis cellulose-graft-polycaprolactone copolymer (2,3-di-O-PCL-cellulose by a new route

    Directory of Open Access Journals (Sweden)

    K. L. Wang

    2017-12-01

    Full Text Available A new and convenient route to the regiocontrolled synthesis of a cellulose-based derivate copolymer (2,3-di-O-polycaprolactone-cellulose grafting ε-caprolactone (ε-CL from α-cellulose, cellulose-graft-polycaprolactone (cellulose-g-PCL, by a classical ring-opening polymerization (ROP reaction, using stannous octoate (Sn(Oct2 as catalyst, in 68% concentration of zinc chloride aqueous solution at 120 °C was presented. By controlling the hydroxyl of cellulose/ε-CL, catalyst/monomer ratio and the reaction time, the molecular architecture of the copolymers can be altered. The solubility of cellulose in zinc chloride aqueous was indicated by UV/VIS spectrometer and rheological measurements. The structures and thermal properties of cellulose-g-polycaprolactone copolymers were characterized using Fourier Transform Infrared (FT-IR, Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR, X-ray Diffraction (XRD, Thermogravimetric Analysis (TGA, Differential Scanning Calorimetry (DSC and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The interesting results confirm that zinc chloride solution can break the intra-molecular hydrogen bonds of cellulose selectively (not only O3H···O5, but also O2H···O6, and has no effect on the inter-molecular hydrogen bonds (O6H···O3. And the grafting reactivity of hydroxyl on cellulose is C2–OH > C3–OH >> C6–OH in zinc chloride solution, and this is clearly different from other researches. Most importantly, this work confirms that the method to regiocontrolled synthesis cellulose-based derivative polymers by regiobreaking hydrogen bonds is feasible. It is strongly believed that the new discovery may give a novel, environmental, simple and inexpensive method to modify cellulose chemically with various side chains grafted on a given hydroxyl, through liberating hydroxyl as reactive group from hydrogen bonds broken selectively by different solvents.

  10. Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.

    Science.gov (United States)

    Griffiths, Jonathan S; North, Helen M

    2017-05-01

    The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

  11. Regenerating cellulose from ionic liquids for an accelerated enzymatic hydrolysis.

    Science.gov (United States)

    Zhao, Hua; Jones, Cecil L; Baker, Gary A; Xia, Shuqian; Olubajo, Olarongbe; Person, Vernecia N

    2009-01-01

    The efficient conversion of lignocellulosic materials into fuel ethanol has become a research priority in producing affordable and renewable energy. The pretreatment of lignocelluloses is known to be key to the fast enzymatic hydrolysis of cellulose. Recently, certain ionic liquids (ILs) were found capable of dissolving more than 10wt% cellulose. Preliminary investigations [Dadi, A.P., Varanasi, S., Schall, C.A., 2006. Enhancement of cellulose saccharification kinetics using an ionic liquid pretreatment step. Biotechnol. Bioeng. 95, 904-910; Liu, L., Chen, H., 2006. Enzymatic hydrolysis of cellulose materials treated with ionic liquid [BMIM]Cl. Chin. Sci. Bull. 51, 2432-2436; Dadi, A.P., Schall, C.A., Varanasi, S., 2007. Mitigation of cellulose recalcitrance to enzymatic hydrolysis by ionic liquid pretreatment. Appl. Biochem. Biotechnol. 137-140, 407-421] suggest that celluloses regenerated from IL solutions are subject to faster saccharification than untreated substrates. These encouraging results offer the possibility of using ILs as alternative and non-volatile solvents for cellulose pretreatment. However, these studies are limited to two chloride-based ILs: (a) 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), which is a corrosive, toxic and extremely hygroscopic solid (m.p. approximately 70 degrees C), and (b) 1-allyl-3-methylimidazolium chloride ([AMIM]Cl), which is viscous and has a reactive side-chain. Therefore, more in-depth research involving other ILs is much needed to explore this promising pretreatment route. For this reason, we studied a number of chloride- and acetate-based ILs for cellulose regeneration, including several ILs newly developed in our laboratory. This will enable us to select inexpensive, efficient and environmentally benign solvents for processing cellulosic biomass. Our data confirm that all regenerated celluloses are less crystalline (58-75% lower) and more accessible to cellulase (>2 times) than untreated substrates. As a result

  12. Reaction kinetics of cellulose hydrolysis in subcritical and supercritical water

    Science.gov (United States)

    Olanrewaju, Kazeem Bode

    The uncertainties in the continuous supply of fossil fuels from the crisis-ridden oil-rich region of the world is fast shifting focus on the need to utilize cellulosic biomass and develop more efficient technologies for its conversion to fuels and chemicals. One such technology is the rapid degradation of cellulose in supercritical water without the need for an enzyme or inorganic catalyst such as acid. This project focused on the study of reaction kinetics of cellulose hydrolysis in subcritical and supercritical water. Cellulose reactions at hydrothermal conditions can proceed via the homogeneous route involving dissolution and hydrolysis or the heterogeneous path of surface hydrolysis. The work is divided into three main parts. First, the detailed kinetic analysis of cellulose reactions in micro- and tubular reactors was conducted. Reaction kinetics models were applied, and kinetics parameters at both subcritical and supercritical conditions were evaluated. The second major task was the evaluation of yields of water soluble hydrolysates obtained from the hydrolysis of cellulose and starch in hydrothermal reactors. Lastly, changes in molecular weight distribution due to hydrothermolytic degradation of cellulose were investigated. These changes were also simulated based on different modes of scission, and the pattern generated from simulation was compared with the distribution pattern from experiments. For a better understanding of the reaction kinetics of cellulose in subcritical and supercritical water, a series of reactions was conducted in the microreactor. Hydrolysis of cellulose was performed at subcritical temperatures ranging from 270 to 340 °C (tau = 0.40--0.88 s). For the dissolution of cellulose, the reaction was conducted at supercritical temperatures ranging from 375 to 395 °C (tau = 0.27--0.44 s). The operating pressure for the reactions at both subcritical and supercritical conditions was 5000 psig. The results show that the rate-limiting step in

  13. Biodegradation of nanocrystalline cellulose by two environmentally-relevant consortia.

    Science.gov (United States)

    Singh, Gargi; Chandoha-Lee, Cody; Zhang, Wei; Renneckar, Scott; Vikesland, Peter J; Pruden, Amy

    2016-11-01

    Nanocellulose is growing in popularity due to its versatile properties and applications. However, there is a void of knowledge regarding the environmental fate of nanocellulose and the response of environmental microbial communities that are historically adapted to non-nano cellulose forms. Given its distinction in terms of size and chemical and physical properties, nanocellulose could potentially resist biodegradation and/or pose a xenobiotic influence on microbial communities during wastewater treatment or in receiving environments. In this study, biodegradation of H 2 SO 4 hydrolyzed nanocrystalline cellulose (HNC) was compared with that of microcrystalline cellulose using two distinct anaerobic cellulose-degrading microbial consortia initially sourced from anaerobic digester (AD) and wetland (W) inocula. Equivalent cellulose masses were dosed and monitored with time by measurement of liberated glucose. HNC biodegraded at slightly faster rate than microcrystalline cellulose (1st order decay constants: 0.62 ± 0.08 wk -1 for HNC versus 0.39 ± 0.05 wk -1 for microcrystalline cellulose for the AD consortium; 0.69 ± 0.04 wk -1 for HNCversus 0.58 ± 0.05 wk -1 for microcrystalline cellulose for the W consortium). 16S rRNA (total bacteria) and cel48 (glycoside hydrolase gene family 48, indicative of cellulose-degrading potential) genes were observed to be more enriched in the HNC condition for both consortia. According to Illumina amplicon sequencing of 16S rRNA genes, the composition of the consortia underwent distinct shifts in concert with HNC versus microcrystalline cellulose degradation. This study demonstrates that the biodegradation of cellulose is not inhibited in the nano-size range, particularly in the crystalline form, though the microbes and pathways involved likely differ. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Extraction of cellulose microcrystalline from galam wood for biopolymer

    Science.gov (United States)

    Ismail, Ika; Sa'adiyah, Devy; Rahajeng, Putri; Suprayitno, Abdi; Andiana, Rocky

    2018-04-01

    Consumption of plastic raw materials tends to increase, but until now the meet of the consumption of plastic raw are still low, even some are still imported. Nowadays, Indonesia's plastic needs are supported by petrochemicals where raw materials are still dependent abroad and petropolymer raw materials are derived from petroleum which will soon be depleted due to rising petroleum needs. Therefore, various studies have been conducted to develop natural fiber-based polymers that are biodegradable and abundant in nature. It is because the natural polymer production process is very efficient and very environmentally friendly. There have been many studies of biopolymers especially natural fiber-based polymers from plants, due to plants containing cellulose, hemicellulose and lignin. However, cellulose is the only one who has crystalline structures. Cellulose has a high crystality compared to amorphous lignin and hemicellulose. In this study, extracted cellulose as biopolymer and amplifier on composite. The cellulose is extracted from galam wood from East Kalimantan. Cellulose extraction will be obtained in nano / micro form through chemical and mechanical treatment processes. The chemical treatment of cellulose extraction is alkalinization process using NaOH solution, bleaching using NaClO2 and acid hydrolysis using sulfuric acid. After chemical treatment, ultrasonic mechanical treatment is made to make cellulose fibers into micro or nano size. Besides, cellulose results will be characterized. Characterization was performed to analyze molecules of cellulose compounds extracted from plants using Fourier Transformation Infra Red (FTIR) testing. XRD testing to analyze cellulose crystallinity. Scanning Electron Microscope (SEM) test to analyze morphology and fiber size.

  15. Composite edible films based on hydroxypropyl methyl cellulose reinforced with microcrystalline cellulose nanoparticles

    Science.gov (United States)

    It has been stated that hydroxypropyl methyl cellulose (HPMC) based films have promising applications in the food industry because of their environmental appeal, low cost, flexibility and transparency. Nevertheless, their mechanical and moisture barrier properties should be improved. The aim of th...

  16. Chemical modification of cellulose extracted from sugarcane bagasse: Preparation of hydroxyethyl cellulose

    Directory of Open Access Journals (Sweden)

    E.S. Abdel-Halim

    2014-07-01

    Full Text Available Cellulose was extracted from sugarcane bagasse by alkaline extraction with sodium hydroxide followed by delignification/bleaching using sodium chlorite/hexamethylenetetramine system. Factors affecting extraction process, including sodium hydroxide concentration, hexamethylenetetramine concentration and temperature were studied and optimum conditions for alkaline extraction were found to be boiling finely ground bagasse under reflux in 1 N sodium hydroxide solution and then carrying out the delignification/bleaching treatment at 95 °C using 5 g/l sodium chlorite together with 0.02 g/l hexamethylenetetramine. The extracted cellulose was used in the preparation of hydroxyethyl cellulose through reaction with ethylene oxide in alkaline medium. Factors affecting the hydroxyethylation reaction, like sodium hydroxide concentration during the alkali formation step, ethylene oxide concentration, reaction temperature and reaction duration were studied. Optimum conditions for hydroxyethylation reaction were using 20% NaOH solution and 200% ethylene oxide (based on weight of cellulose, carrying out the reaction at 100 °C for 60 min.

  17. Optimizing cellulose fibrillation for the production of cellulose nanofibrils by a disk grinder

    Science.gov (United States)

    Chuanshuang Hu; Yu Zhao; Kecheng Li; J.Y. Zhu; Roland Gleisner

    2015-01-01

    The fibrillation of a bleached kraft eucalyptus pulp was investigated by means of a laboratory-scale disk grinder for the production of cellulose nanofibrils (CNF), while the parameters disk rotating speed, solid loading, and fibrillation duration were varied. The cumulative energy consumption was monitored during fibrillation. The degree of polymerization (DP) and...

  18. Twin carbons: The carbonization of cellulose or carbonized cellulose coated with a conducting polymer, polyaniline

    Czech Academy of Sciences Publication Activity Database

    Bober, Patrycja; Kovářová, Jana; Pfleger, Jiří; Stejskal, Jaroslav; Trchová, Miroslava; Novák, I.; Berek, D.

    2016-01-01

    Roč. 109, November (2016), s. 836-842 ISSN 0008-6223 R&D Projects: GA ČR(CZ) GA13-00270S Institutional support: RVO:61389013 Keywords : cellulose * carbon * polyaniline Subject RIV: CD - Macromolecular Chemistry Impact factor: 6.337, year: 2016

  19. Uniaxially aligned electrospun all-cellulose nanocomposite nanofibers reinforced with cellulose nanocrystals: scaffold for tissue engineering.

    Science.gov (United States)

    He, Xu; Xiao, Qiang; Lu, Canhui; Wang, Yaru; Zhang, Xiaofang; Zhao, Jiangqi; Zhang, Wei; Zhang, Ximu; Deng, Yulin

    2014-02-10

    Uniaxially aligned cellulose nanofibers with well oriented cellulose nanocrystals (CNCs) embedded were fabricated via electrospinning using a rotating drum as the collector. Scanning electron microscope (SEM) images indicated that most cellulose nanofibers were uniaxially aligned. The incorporation of CNCs into the spinning dope resulted in more uniform morphology of the electrospun cellulose/CNCs nanocomposite nanofibers (ECCNN). Polarized light microscope (PLM) and transmission electron microscope (TEM) showed that CNCs dispersed well in ECCNN nonwovens and achieved considerable orientation along the long axis direction. This unique hierarchical microstructure of ECCNN nonwovens gave rise to remarkable enhancement of their physical properties. By incorporating 20% loading (in weight) of CNCs, the tensile strength and elastic modulus of ECCNN along the fiber alignment direction were increased by 101.7 and 171.6%, respectively. Their thermal stability was significantly improved as well. In addition, the ECCNN nonwovens were assessed as potential scaffold materials for tissue engineering. It was elucidated from MTT tests that the ECCNN were essentially nontoxic to human cells. Cell culture experiments demonstrated that cells could proliferate rapidly not only on the surface but also deep inside the ECCNN. More importantly, the aligned nanofibers of ECCNN exhibited a strong effect on directing cellular organization. This feature made the scaffold particularly useful for various artificial tissues or organs, such as blood vessel, tendon, nerve, and so on, in which cell orientation was crucial for their performance.

  20. Polymer Nanocomposites with Cellulose Nanocrystals Featuring Adaptive Surface Groups.

    Science.gov (United States)

    Natterodt, Jens C; Sapkota, Janak; Foster, E Johan; Weder, Christoph

    2017-02-13

    Cellulose nanocrystals (CNCs) are mechanically rigid, toxicologically benign, fiber-like nanoparticles. They can easily be extracted from renewable biosources and have attracted significant interest as reinforcing fillers in polymers. We here report the modification of CNCs with the 2-ureido-4[1H]pyrimidinone (UPy) motif as an adaptive compatibilizer, which permits the dispersion of UPy-modified CNCs in nonpolar as well as polar media. In toluene, the UPy motifs appear to form intra-CNC dimers, so that the particles are somewhat hydrophobized and well-dispersible in this nonpolar solvent. By contrast, the UPy motifs dissociate in DMF and promote dispersibility through interactions with this polar solvent. We have exploited this adaptiveness and integrated UPy-modified CNCs into nonpolar and polar host polymers, which include different poly(ethylene)s, a polystyrene-block-polybutadiene-block-polystyrene elastomer and poly(ethylene oxide-co-epichlorohydrin). All nanocomposites display an increase of stiffness and strength in comparison to the neat polymer, and some compositions retain a high elongation at break, even at a filler content of 15% w/w.

  1. Formation of carboxymethyl cellulose hydrogel containing silver nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Seok; Kuang, Jia; Gwon, Hui Jeong; Lim, Youn Mook; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-12-15

    Silver nanoparticles (AgNPs) can be used in the areas such as integrate circuit, cell electrode and antimicrobial deodorant. In this study, AgNPs have been prepared by using AgNO{sub 3} aqueous solution in the carboxymethyl cellulose (CMC) hydrogel. CMC powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make CMC hydrogel. CMC hydrogels were dipped into 1.0 x 10{sup -2} M AgNO{sub 3} solution for 1 hour. After that, the swollen hydrogels were irradiated by gamma-ray for the formation of AgNPs. The characteristics of silver nanoparticles in the CMC hydrogels were monitored by UV-Vis and the morphological study and dispersed coefficient of particles were investigated by FE-SEM/EDX. It was observed that the sodium salt in the CMC is crucial to the formation of silver nanoparticle. Finally, antibacterial tests indiacted that the hydrogel containing silver nanoparticle has antibacterial activity.

  2. Ultrafine particles

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Weschler, Charles J.; Wierzbicka, Aneta

    2013-01-01

    Particle number (PN) concentrations (10-300 nm in size) were continuously measured over a period of ∼45 h in 56 residences of nonsmokers in Copenhagen, Denmark. The highest concentrations were measured when occupants were present and awake (geometric mean, GM: 22.3 × 103 cm-3), the lowest when...... the homes were vacant (GM: 6.1 × 103 cm-3) or the occupants were asleep (GM: 5.1 × 103 cm-3). Diary entries regarding occupancy and particle related activities were used to identify source events and apportion the daily integrated exposure among sources. Source events clearly resulted in increased PN...... concentrations and decreased average particle diameter. For a given event, elevated particle concentrations persisted for several hours after the emission of fresh particles ceased. The residential daily integrated PN exposure in the 56 homes ranged between 37 × 103 and 6.0 × 106 particles per cm3·h/day (GM: 3...

  3. Coarse-grained model for the interconversion between different crystalline cellulose allomorphs

    Energy Technology Data Exchange (ETDEWEB)

    Langan, Paul [ORNL

    2012-01-01

    We present the results of Langevin dynamics simulations on a coarse grained model for crystalline cellulose. In particular, we analyze two different cellulose crystalline forms: cellulose I (the natural form of cellulose) and cellulose IIII (obtained after cellulose I is treated with anhydrous liquid ammonia). Cellulose IIII has been the focus of wide interest in the field of cellulosic biofuels as it can be efficiently hydrolyzed to glucose (its enzymatic degradation rates are up to 5 fold higher than those of cellulose I ). In turn, glucose can eventually be fermented into fuels. The coarse-grained model presented in this study is based on a simplified geometry and on an effective potential mimicking the changes in both intracrystalline hydrogen bonds and stacking interactions during the transition from cellulose I to cellulose IIII. The model accurately reproduces both structural and thermomechanical properties of cellulose I and IIII. The work presented herein describes the structural transition from cellulose I to cellulose IIII as driven by the change in the equilibrium state of two degrees of freedom in the cellulose chains. The structural transition from cellulose I to cellulose IIII is essentially reduced to a search for optimal spatial arrangement of the cellulose chains.

  4. Cellulose whisker/epoxy resin nanocomposites.

    Science.gov (United States)

    Tang, Liming; Weder, Christoph

    2010-04-01

    New nanocomposites composed of cellulose nanofibers or "whiskers" and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of approximately 10 and approximately 84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185-192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtures and subsequent curing. The whisker content was systematically varied between 4 and 24% v/v. Electron microscopy studies suggest that the whiskers are evenly dispersed within the epoxy matrix. Dynamic mechanical thermoanalysis revealed that the glass transition temperature (T(g)) of the materials was not significantly influenced by the incorporation of the cellulose filler. Between room temperature and 150 degrees C, i.e., below T(g), the tensile storage moduli (E') of the nanocomposites increased modestly, for example from 1.6 GPa for the neat polymer to 4.9 and 3.6 GPa for nanocomposites comprising 16% v/v tunicate or cotton whiskers. The relative reinforcement was more significant at 185 degrees C (i.e., above T(g)), where E' was increased from approximately 16 MPa (neat polymer) to approximately 1.6 GPa (tunicate) or approximately 215 MPa (cotton). The mechanical properties of the new materials are well-described by the percolation model and are the result of the formation of a percolating whisker network in which stress transfer is facilitated by strong interactions between the whiskers.

  5. Printed optically transparent graphene cellulose electrodes

    Science.gov (United States)

    Sinar, Dogan; Knopf, George K.; Nikumb, Suwas; Andrushchenko, Anatoly

    2016-02-01

    Optically transparent electrodes are a key component in variety of products including bioelectronics, touch screens, flexible displays, low emissivity windows, and photovoltaic cells. Although highly conductive indium tin oxide (ITO) films are often used in these electrode applications, the raw material is very expensive and the electrodes often fracture when mechanically stressed. An alternative low-cost material for inkjet printing transparent electrodes on glass and flexible polymer substrates is described in this paper. The water based ink is created by using a hydrophilic cellulose derivative, carboxymethyl cellulose (CMC), to help suspend the naturally hydrophobic graphene (G) sheets in a solvent composed of 70% DI water and 30% 2-butoxyethanol. The CMC chain has hydrophobic and hydrophilic functional sites which allow adsorption on G sheets and, therefore, permit the graphene to be stabilized in water by electrostatic and steric forces. Once deposited on the functionalized substrate the electrical conductivity of the printed films can be "tuned" by decomposing the cellulose stabilizer using thermal reduction. The entire electrode can be thermally reduced in an oven or portions of the electrode thermally modified using a laser annealing process. The thermal process can reduce the sheet resistance of G-CMC films to < 100 Ω/sq. Experimental studies show that the optical transmittance and sheet resistance of the G-CMC conductive electrode is a dependent on the film thickness (ie. superimposed printed layers). The printed electrodes have also been doped with AuCl3 to increase electrical conductivity without significantly increasing film thickness and, thereby, maintain high optical transparency.

  6. Particle cosmology

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The understanding of the Universe at the largest and smallest scales traditionally has been the subject of cosmology and particle physics, respectively. Studying the evolution of the Universe connects today's large scales with the tiny scales in the very early Universe and provides the link between the physics of particles and of the cosmos. This series of five lectures aims at a modern and critical presentation of the basic ideas, methods, models and observations in today's particle cosmology.

  7. OBTAINING OF MICROCRYSTALLINE CELLULOSE FROM PLANT MATERIAL

    OpenAIRE

    Барбаш, Валерій Анатолійович; Нагорна, Юлія Миколаївна

    2015-01-01

    The process of obtaining microcrystalline cellulose from fibers of technical and stalks of cereal plants (hemp, flax, kenaf, corn, wheat and miscanthus) with using of soda cooking, acid treatment, bleaching and hydrolysis were investigated. It was founded that soda cooking to help reducing the residual lignin content in industrial fibers plants from 4,6 to 12,4 % and for stalks of cereal plants from 13.4 to 20.9 % and mineral substances for fibers of industrial plants from 1,2 to 2,7 % and fo...

  8. Particle physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  9. Particle Physics

    CERN Document Server

    Martin, B R

    2008-01-01

    An essential introduction to particle physics, with coverage ranging from the basics through to the very latest developments, in an accessible and carefully structured text. Particle Physics: Third Edition is a revision of a highly regarded introduction to particle physics. In its two previous editions this book has proved to be an accessible and balanced introduction to modern particle physics, suitable for those students needed a more comprehensive introduction to the subject than provided by the 'compendium' style physics books. In the Third Edition the standard mod

  10. The Pt-enriched PtNi alloy surface and its excellent catalytic performance in hydrolytic hydrogenation of cellulose.

    Science.gov (United States)

    Liang, Guanfeng; He, Limin; Arai, Masahiko; Zhao, Fengyu

    2014-05-01

    Ni-based catalysts are currently a subject of intense research in the hydrolytic hydrogenation of cellulose. We previously reported that Ni/ZSM-5 catalyst gave high yield of hexitols. However, Ni-based catalysts suffered fast deactivation in hot-compressed water. In this follow-up study we designed highly active Ni-based bimetallic catalysts with excellent hydrothermal stability for the hydrolytic hydrogenation of microcrystalline cellulose. PtNi/ZSM-5 shows a 76.9 % yield of hexitols, which is the best obtained so far in the hydrolytic hydrogenation of microcrystalline cellulose over Ni-based catalysts. Furthermore, the yield of hexitols remained greater than 55 % after the catalyst was reused for 4 times. The results showed that PtNi nanoparticles were formed with a Pt-enriched alloy surface as confirmed by XRD, H2-TPR (temperature-programmed H2 reduction), XPS (X-ray photoelectron spectroscopy), and H2-TPD (temperature-programmed H2 desorption). The surface features of these nano-particles were characterized by CO-TPD (temperature-programmed CO desorption), CO-FTIR (CO adsorption FTIR spectroscopy), HRTEM (high resolution TEM), and O2-TPO (temperature programmed oxidation) and this special surface structure may be responsible for the high activity, selectivity, and stability in the hydrolytic hydrogenation of cellulose in hot-compressed water. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Understanding plant cellulose synthases through a comprehensive investigation of the cellulose synthase family sequences.

    Directory of Open Access Journals (Sweden)

    Andrew eCarroll

    2011-03-01

    Full Text Available The development of cellulose as an organizing structure in the plant cell wall was a key event in both the initial colonization and the subsequent domination of the terrestrial ecosystem by vascular plants. A wealth of experimental data has demonstrated the complicated genetic interactions required to form the large synthetic complex that synthesizes cellulose. However, these results are lacking an extensive analysis of the evolution, specialization, and regulation of the proteins that compose this complex. Here we perform an in-depth analysis of the sequences in the cellulose synthase (CesA family. We investigate the phylogeny of the CesA family, with emphasis on evolutionary specialization. We define specialized subfamilies and identify the class-specific regions within the CesA sequence that may explain this specialization. We investigate changes in regulation of CesAs by looking at the conservation of proposed phosphorylation sites. We investigate the conservation of sites where mutations have been documented that impair cellulose synthase function, and compare these sites to those observed in the closest cellulose synthase-like (Csl families to better understand what regions may separate the CesAs from other Csls. Finally we identify two positions with strong conservation of the aromatic trait, but lacking conservation of amino acid identity, which may represent residues important for positioning the sugar substrate for catalysis. These analyses provide useful tools for understanding characterized mutations and post-translational modifications, and for informing further experiments to probe CesA assembly, regulation, and function through site-directed mutagenesis or domain swapping experiments.

  12. Carbon-supported base metal nanoparticles : Cellulose at work

    NARCIS (Netherlands)

    Hoekstra, Jacco; Versluijs-Helder, Marjan; Vlietstra, Edward J.; Geus, John W.; Jenneskens, Leonardus W.

    2015-01-01

    Pyrolysis of base metal salt loaded microcrystalline cellulose spheres gives a facile access to carbon-supported base metal nanoparticles, which have been characterized with temperature-dependent XRD, SEM, TEM, ICP-MS and elemental analysis. The role of cellulose is multifaceted: 1) it facilitates a

  13. Cellulose sulphuric acid as a biodegradable catalyst for conversion ...

    Indian Academy of Sciences (India)

    Cellulose sulphuric acid as a biodegradable catalyst for conversion of aryl amines into azides at room temperature under mild conditions. Firouzeh Nesmati Ali Elhampour. Volume 124 Issue 4 July 2012 ... Keywords. Cellulose sulphuric acid; aryl azides; diazotization; biodegradable. ... Supplementary Material. supp18.pdf ...

  14. Single Molecule Study of Cellulase Hydrolysis of Crystalline Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.-S.; Luo, Y.; Baker, J. O.; Zeng, Y.; Himmel, M. E.; Smith, S.; Ding, S.-Y.

    2009-12-01

    This report seeks to elucidate the role of cellobiohydrolase-I (CBH I) in the hydrolysis of crystalline cellulose. A single-molecule approach uses various imaging techniques to investigate the surface structure of crystalline cellulose and changes made in the structure by CBH I.

  15. Cellulose nanomaterials as green nanoreinforcements for polymer nanocomposites

    Science.gov (United States)

    Dufresne, Alain

    2017-12-01

    Unexpected and attractive properties can be observed when decreasing the size of a material down to the nanoscale. Cellulose is no exception to the rule. In addition, the highly reactive surface of cellulose resulting from the high density of hydroxyl groups is exacerbated at this scale. Different forms of cellulose nanomaterials, resulting from a top-down deconstruction strategy (cellulose nanocrystals, cellulose nanofibrils) or bottom-up strategy (bacterial cellulose), are potentially useful for a large number of industrial applications. These include the paper and cardboard industry, use as reinforcing filler in polymer nanocomposites, the basis for low-density foams, additives in adhesives and paints, as well as a wide variety of filtration, electronic, food, hygiene, cosmetic and medical products. This paper focuses on the use of cellulose nanomaterials as a filler for the preparation of polymer nanocomposites. Impressive mechanical properties can be obtained for these materials. They obviously depend on the type of nanomaterial used, but the crucial point is the processing technique. The emphasis is on the melt processing of such nanocomposite materials, which has not yet been properly resolved and remains a challenge. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  16. Effect of antimicrobial agents on cellulose acetate nano composites properties

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo, E-mail: francisco.rodriguez.m@usach.cl [Center for the Development of Nanoscience and Nanotechnology (CEDENNA). Universidad de Santiago de Chile. Faculty of Technology. Department of Food Science and Technology. Food Packaging Laboratory. Santiago (Chile)

    2011-07-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  17. Potentials of cellulosic wastes in media formulation | Nwodo ...

    African Journals Online (AJOL)

    Potential use of cellulosic wastes as carbon and energy sources in selective media formulations was investigated. Two agar media, Czapek-Dox and Sabouraud's agar, were modified by substituting their carbon sources with cellulose, sawdust and sugarcane pulps. Then, two fungi; Aspergillus niger ANL301 and ...

  18. Cellulose nanocrystals the next big nano-thing?

    Science.gov (United States)

    Michael T. Postek; Andras Vladar; John Dagata; Natalia Farkas; Bin Ming; Ronald Sabo; Theodore H. Wegner; James Beecher

    2008-01-01

    Biomass surrounds us from the smallest alga to the largest redwood tree. Even the largest trees owe their strength to a newly-appreciated class of nanomaterials known as cellulose nanocrystals (CNC). Cellulose, the world’s most abundant natural, renewable, biodegradable polymer, occurs as whisker like microfibrils that are biosynthesized and deposited in plant material...

  19. Life Cycle Assessment of man-made cellulose fibres

    NARCIS (Netherlands)

    Shen, L.; Patel, M.K.

    2010-01-01

    The production of textile materials has undergone dramatic changes in the last century. Man-made cellulose fibres have played an important role for more than 70 years. Today, the man-made cellulose fibre industry is the worldwide second largest biorefinery (next to the paper industry). In the last

  20. Determination of cellulose I crystallinity by FT-Raman spectroscopy

    Science.gov (United States)

    Umesh P. Agarwal; Richard S. Reiner; Sally A. Ralph

    2009-01-01

    Two new methods based on FT-Raman spectroscopy, one simple, based on band intensity ratio, and the other, using a partial least-squares (PLS) regression model, are proposed to determine cellulose I crystallinity. In the simple method, crystallinity in semicrystalline cellulose I samples was determined based on univariate regression that was first developed using the...

  1. Cellulose synthesizing Complexes in Vascular Plants andProcaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard M, Jr; Saxena, Inder Mohan

    2009-07-07

    Continuing the work initiated under DE-FG03-94ER20145, the following major accomplishments were achieved under DE-FG02-03ER15396 from 2003-2007: (a) we purified the acsD gene product of the Acetobacter cellulose synthase operon as well as transferred the CesA cellulose gene from Gossypium into E. coli in an attempt to crystallize this protein for x-ray diffraction structural analysis; however, crystallization attempts proved unsuccessful; (b) the Acetobacter cellulose synthase operon was successfully incorporated into Synechococcus, a cyanobacterium2; (c) this operon in Synechococcus was functionally expressed; (d) we successfully immunolabeled Vigna cellulose and callose synthase components and mapped their distribution before and after wounding; (e) we developed a novel method to produce replicas of cellulose synthases in tobacco BY-2 cells, and we demonstrated the cytoplasmic domain of the rosette TC; (f) from the moss Physcomitrella, we isolated two full-length cDNA sequences of cellulose synthase (PpCesA1 and PpCesA2) and attempted to obtain full genomic DNA sequences; (g) we examined the detailed molecular structure of a new form of non-crystalline cellulose known as nematic ordered cellulose (=NOC)3.

  2. Evolving Microbial Communities in Cellulose-Fed Microbial Fuel Cell

    Directory of Open Access Journals (Sweden)

    Renata Toczyłowska-Mamińska

    2018-01-01

    Full Text Available The abundance of cellulosic wastes make them attractive source of energy for producing electricity in microbial fuel cells (MFCs. However, electricity production from cellulose requires obligate anaerobes that can degrade cellulose and transfer electrons to the electrode (exoelectrogens, and thus most previous MFC studies have been conducted using two-chamber systems to avoid oxygen contamination of the anode. Single-chamber, air-cathode MFCs typically produce higher power densities than aqueous catholyte MFCs and avoid energy input for the cathodic reaction. To better understand the bacterial communities that evolve in single-chamber air-cathode MFCs fed cellulose, we examined the changes in the bacterial consortium in an MFC fed cellulose over time. The most predominant bacteria shown to be capable electron generation was Firmicutes, with the fermenters decomposing cellulose Bacteroidetes. The main genera developed after extended operation of the cellulose-fed MFC were cellulolytic strains, fermenters and electrogens that included: Parabacteroides, Proteiniphilum, Catonella and Clostridium. These results demonstrate that different communities evolve in air-cathode MFCs fed cellulose than the previous two-chamber reactors.

  3. CELLULOSE EXTRACTION FROM PALM KERNEL CAKE USING LIQUID PHASE OXIDATION

    Directory of Open Access Journals (Sweden)

    FARM YAN YAN

    2009-03-01

    Full Text Available Cellulose is widely used in many aspect and industries such as food industry, pharmaceutical, paint, polymers, and many more. Due to the increasing demand in the market, studies and work to produce cellulose are still rapidly developing. In this work, liquid phase oxidation was used to extract cellulose from palm kernel cake to separate hemicellulose, cellulose and lignin. The method is basically a two-step process. Palm kernel cake was pretreated in hot water at 180°C and followed by liquid oxidation process with 30% H2O2 at 60°C at atmospheric pressure. The process parameters are hot water treatment time, ratio of palm kernel cake to H2O2, liquid oxidation reaction temperature and time. Analysis of the process parameters on production cellulose from palm kernel cake was performed by using Response Surface Methodology. The recovered cellulose was further characterized by Fourier Transform Infrared (FTIR. Through the hot water treatment, hemicellulose in the palm kernel cake was successfully recovered as saccharides and thus leaving lignin and cellulose. Lignin was converted to water soluble compounds in liquid oxidation step which contains small molecular weight fatty acid as HCOOH and CH3COOH and almost pure cellulose was recovered.

  4. Endurance of high molecular weight carboxymethyl cellulose in corrosive environments

    Science.gov (United States)

    Murodov, M. M.; Rahmanberdiev, G. R.; Khalikov, M. M.; Egamberdiev, E. A.; Negmatova, K. C.; Saidov, M. M.; Mahmudova, N.

    2012-07-01

    Lignin obtained from the waste cooking liquor, formed after soda pulping process, is used as an inhibitor of NaCMC thermo oxidative degradation in presence of in extreme conditions during drilling oil wells. In this paper the schematic process of obtaining NaCMC by the principle of "monoapparat" on the basis of cellulose produced by non-wood cellulose materials is presented.

  5. Characterization of cellulose based sponges for wound dressings

    NARCIS (Netherlands)

    Gustaite, S.; Kazlauske, J.; Bobokalonov, J.; Perni, S.; Dutschk, Victoria; Liesiene, J.; Prokopovich, P.

    2015-01-01

    Cellulose based sponges were developed by freeze-drying of regenerated cellulose gels and characterizedas a potential wound dressing. Morphological characteristics were analyzed by means of micro-computedtomography. The results showed that the porosity of the sponges reached 75%, the pores were

  6. Cellulose nanocrystals from acacia bark-Influence of solvent extraction.

    Science.gov (United States)

    Taflick, Ticiane; Schwendler, Luana A; Rosa, Simone M L; Bica, Clara I D; Nachtigall, Sônia M B

    2017-08-01

    The isolation of cellulose nanocrystals from different lignocellulosic materials has shown increased interest in academic and technological research. These materials have excellent mechanical properties and can be used as nanofillers for polymer composites as well as transparent films for various applications. In this work, cellulose isolation was performed following an environmental friendly procedure without chlorine. Cellulose nanocrystals were isolated from the exhausted acacia bark (after the industrial process of extracting tannin) with the objective of evaluating the effect of the solvent extraction steps on the characteristics of cellulose and cellulose nanocrystals. It was also assessed the effect of acid hydrolysis time on the thermal stability, morphology and size of the nanocrystals, through TGA, TEM and light scattering analyses. It was concluded that the extraction step with solvents was important in the isolation of cellulose, but irrelevant in the isolation of cellulose nanocrystals. Light scattering experiments indicated that 30min of hydrolysis was long enough for the isolation of cellulose nanocrystals. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Calculation of single chain cellulose elasticity using fully atomistic modeling

    Science.gov (United States)

    Xiawa Wu; Robert J. Moon; Ashlie Martini

    2011-01-01

    Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is...

  8. Assessment of Quality Characteristics of Cellulose, Sheep and Goat ...

    African Journals Online (AJOL)

    Small intestines of 12 West African Dwarf (WAD) sheep and those of 12 Red Sokoto goats obtained from an abattoir were converted into casings. The imported cellulose casing used for the study was obtained from a sausage manufacturing company. Cellulose casing had the widest diameter of 35.00mm followed by ...

  9. Single-molecule study of oxidative enzymatic deconstruction of cellulose.

    Science.gov (United States)

    Eibinger, Manuel; Sattelkow, Jürgen; Ganner, Thomas; Plank, Harald; Nidetzky, Bernd

    2017-10-12

    LPMO (lytic polysaccharide monooxygenase) represents a unique paradigm of cellulosic biomass degradation by an oxidative mechanism. Understanding the role of LPMO in deconstructing crystalline cellulose is fundamental to the enzyme's biological function and will help to specify the use of LPMO in biorefinery applications. Here we show with real-time atomic force microscopy that C1 and C4 oxidizing types of LPMO from Neurospora crassa (NcLPMO9F, NcLPMO9C) bind to nanocrystalline cellulose with high preference for the very same substrate surfaces that are also used by a processive cellulase (Trichoderma reesei CBH I) to move along during hydrolytic cellulose degradation. The bound LPMOs, however, are immobile during their adsorbed residence time ( ~ 1.0 min for NcLPMO9F) on cellulose. Treatment with LPMO resulted in fibrillation of crystalline cellulose and strongly ( ≥ 2-fold) enhanced the cellulase adsorption. It also increased enzyme turnover on the cellulose surface, thus boosting the hydrolytic conversion.Understanding the role of enzymes in biomass depolymerization is essential for the development of more efficient biorefineries. Here, the authors show by atomic force microscopy the real-time mechanism of cellulose deconstruction by lytic polysaccharide monooxygenases.

  10. Direct compression properties of microcrystalline cellulose and its ...

    African Journals Online (AJOL)

    The influence of silicified microcrystalline cellulose (SMCC) on the flow, compaction and tableting properties of metronidazole powder was investigated. The study compared medium grades of both SMCC and standard microcrystalline cellulose (MCC) as direct compressible excipients. The bulk densities, Hausner quotient ...

  11. Atomistic Simulation of Frictional Sliding Between Cellulose Iß Nanocrystals

    Science.gov (United States)

    Xiawa Wu; Robert J. Moon; Ashlie Martini

    2013-01-01

    Sliding friction between cellulose Iß nanocrystals is studied using molecular dynamics simulation. The effects of sliding velocity, normal load, and relative angle between sliding surface are predicted, and the results analyzed in terms of the number of hydrogen bonds within and between the cellulose chains. We find that although the observed friction trends can be...

  12. Effect of antimicrobial agents on cellulose acetate nano composites properties

    International Nuclear Information System (INIS)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo

    2011-01-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  13. Development of the metrology and imaging of cellulose nanocrystals

    Science.gov (United States)

    Michael T. Postek; Andras Vladar; John Dagata; Natalia Farkas; Bin Ming; Ryan Wagner; Arvind Raman; Robert J. Moon; Ronald Sabo; Theodore H. Wegner; James Beecher

    2011-01-01

    The development of metrology for nanoparticles is a significant challenge. Cellulose nanocrystals (CNCs) are one group of nanoparticles that have high potential economic value but present substantial challenges to the development of the measurement science. Even the largest trees owe their strength to this newly appreciated class of nanomaterials. Cellulose is the...

  14. Microcrystalline cellulose obtained from plant as a pharmaceutical ...

    African Journals Online (AJOL)

    This study was aimed at developing pharmaceutical grade microcrystalline cellulose from Chasmanthera dependens stem phloem fibres as a tablet excipient. The microcrystalline cellulose coded CD-MCC, was obtained from the phloem fibres by a two-stage sodium hydroxide delignification process followed by sodium ...

  15. Mechanization of Continuous Production of Powdered Cellulose Technology

    Science.gov (United States)

    Prosvirnikov, D. B.; Safin, R. G.; Akhmetshin, I. R.; Taimarov, M. A.; Timerbaev, N. F.

    2017-07-01

    The article presents the mechanization of the process for obtaining powdered cellulose using the technology of steam explosion treatment of lignocellulosic material. The presented unit combines the methods of steam explosion treatment and acid hydrolysis of cellulose-containing raw materials.

  16. Alkali and bleach treatment of the extracted cellulose from pineapple ...

    African Journals Online (AJOL)

    We successfully extracted cellulose from pineapple leaves (Ananas comosus) using alkali treatment and bleaching. Alkali treatment was done using aqueous sodium hydroxide while bleaching was done using acetate buffer and aqueous sodium chlorite. The extracted cellulose was characterized using Scanning electron ...

  17. Cellulose microfibril deposition: coordinated activity at the plant plasma membrane

    NARCIS (Netherlands)

    Lindeboom, J.J.; Mulder, B.; Vos, J.W.; Ketelaar, M.J.; Emons, A.M.C.

    2008-01-01

    Plant cell wall production is a membrane-bound process. Cell walls are composed of cellulose microfibrils, embedded inside a matrix of other polysaccharides and glycoproteins. The cell wall matrix is extruded into the existing cell wall by exocytosis. This same process also inserts the cellulose

  18. Iodine-Catalyzed Synthesis of Mixed Cellulose Esters

    Science.gov (United States)

    A novel method for the preparation of cellulose mixed acetate is described herein, involving the concurrent use of iodine and mixed anhydride. The method is simple, rapid, efficient, and solvent-less. With this method, cellulose mixed esters has been synthesized. ...

  19. Is the combination of cellulosic polymers and anionic surfactants a good strategy for ensuring physical stability of BCS Class II drug nanosuspensions?

    Science.gov (United States)

    Bilgili, Ecevit; Li, Meng; Afolabi, Afolawemi

    2016-01-01

    Ensuring the physical stability of drug nanosuspensions prepared via wet media milling has been a challenge for pharmaceutical scientists. The aim of this study is to assess the combined use of non-ionic cellulosic polymers and anionic surfactants in stabilizing multiple drug nanosuspensions. Particle size of five drugs, i.e. azodicarbonamide (AZD), fenofibrate (FNB), griseofulvin (GF), ibuprofen (IBU) and phenylbutazone (PB) was reduced separately in an aqueous solution of hydroxypropyl cellulose (HPC) with/without sodium dodecyl sulfate (SDS) via a stirred media mill. Laser diffraction, scanning electron microscopy, thermal analysis, rheometry and electrophoresis were used to evaluate the breakage kinetics, storage stability, electrostatic repulsion and stabilizer adsorption. Without SDS, drug particles exhibited aggregation to different extents; FNB and GF particles aggregated the most due to low zeta potential and insufficient steric stabilization. Although aggregation in all milled suspensions was reduced due to HPC-SDS combination, FNB and IBU showed notable growth during 7-day storage. It is concluded that the combination of non-ionic cellulosic polymers and anionic surfactants is generally viable for ensuring the physical stability of wet-milled drug nanosuspensions, provided that the surfactant concentration is optimized to mitigate the Ostwald ripening, whereas cellulosic polymers alone may provide stability for some drug suspensions.

  20. Preparation and characterization of nanoparticles of carboxymethyl cellulose acetate butyrate containing acyclovir

    Science.gov (United States)

    Vedula, Venkata Bharadwaz; Chopra, Maulick; Joseph, Emil; Mazumder, Sonal

    2016-02-01

    Nanoparticles of carboxymethyl cellulose acetate butyrate complexed with the poorly soluble antiviral drug acyclovir (ACV) were produced by precipitation process and the formulation process and properties of nanoparticles were investigated. Two different particle synthesis methods were explored—a conventional precipitation method and a rapid precipitation in a multi-inlet vortex mixer. The particles were processed by rotavap followed by freeze-drying. Particle diameters as measured by dynamic light scattering were dependent on the synthesis method used. The conventional precipitation method did not show desired particle size distribution, whereas particles prepared by the mixer showed well-defined particle size ~125-450 nm before and after freeze-drying, respectively, with narrow polydispersity indices. Fourier transform infrared spectroscopy showed chemical stability and intactness of entrapped drug in the nanoparticles. Differential scanning calorimetry showed that the drug was in amorphous state in the polymer matrix. ACV drug loading was around 10 wt%. The release studies showed increase in solution concentration of drug from the nanoparticles compared to the as-received crystalline drug.

  1. The Effect of Particle Properties on Hot Particle Spot Fire Ignition

    Science.gov (United States)

    Zak, Casey David

    The ignition of natural combustible material by hot metal particles is an important fire ignition pathway by which wildland and wildland-urban-interface spot fires are started. There are numerous cases reported of wild fires started by clashing power-lines or from sparks generated by machines or engines. Similarly there are many cases reported of fires caused by grinding, welding and cutting sparks. Up to this point, research on hot particle spot fire ignition has largely focused on particle generation and transport. A small number of studies have examined what occurs after a hot particle contacts a natural fuel bed, but until recently the process remained poorly understood. This work describes an investigation of the effect of particle size, temperature and thermal properties on the ability of hot particles to cause flaming ignition of cellulosic fuel beds. Both experimental and theoretical approaches are used, with a focus on understanding the physics underlying the ignition process. For the experimental study, spheres of stainless steel, aluminum, brass and copper are heated in a tube furnace and dropped onto a powdered cellulose fuel bed; the occurrence of flaming ignition or lack thereof is visually observed and recorded. This procedure is repeated a large number of times for each metal type, varying particle diameter from 2 to 11 mm and particle temperature between 575 and 1100°C. The results of these experiments are statistically analyzed to find approximate ignition boundaries and identify boundary trends with respect to the particle parameters of interest. Schlieren images recorded during the ignition experiments are also used to more accurately describe the ignition process. Based on these images, a simple theoretical model of hot particle spot fire ignition is developed and used to explore the experimental trends further. The model under-predicts the minimum ignition temperatures required for small spheres, but agrees qualitatively with the experimental

  2. Physical properties of agave cellulose graft polymethyl methacrylate

    International Nuclear Information System (INIS)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-01-01

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm −1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one

  3. Physical properties of agave cellulose graft polymethyl methacrylate

    Science.gov (United States)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-01

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm-1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  4. Dissolution of cellulose in ionic liquid: A review

    Science.gov (United States)

    Mohd, N.; Draman, S. F. S.; Salleh, M. S. N.; Yusof, N. B.

    2017-02-01

    Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.

  5. Quantification of cellulase activity using cellulose-azure.

    Science.gov (United States)

    Lai, Takwai E; Pullammanappallil, Pratap C; Clarke, William P

    2006-03-15

    Despite wide application of cellulose-azure as a substrate for measuring cellulase activity, there is no quantification of hydrolysis rate or enzymatic activities using this substrate. The aim of this study was to quantify the hydrolysis rate in terms of product formation and dye released using cellulose-azure. The amount of dye released was correlated with the production of glucose and the enzyme concentrations. It is shown that the lack of correlation can be due to (1) repression of the release of the azure-dye when azure-dye accumulates, (2) presence of degradable substrates in the cellulase powder which inflate the glucose measurements and (3) the degradation of cellulose which is not linked to the dye in the cellulose-azure. Based on the lack of correlation, it is recommended that cellulose-azure should only be applied in assays when the aim is to compare relative activities of different enzymatic systems.

  6. Cellulose-reinforced composites: from micro-to nanoscale

    Directory of Open Access Journals (Sweden)

    Alain Dufresne

    2013-01-01

    Full Text Available This paper present the most relevant advances in the fields of: i cellulose fibres surface modification; ii cellulose fibres-based composite materials; and iii nanocomposites based on cellulose whiskers or starch platelet-like nanoparticles. The real breakthroughs achieved in the first topic concern the use of solvent-free grafting process (plasma and the grafting of the matrix at the surface of cellulose fibres through isocyanate-mediated grafting or thanks to "click chemistry". Concerning the second topic, it is worth to mention that for some cellulose/matrix combination and in the presence of adequate aids or specific surface treatment, high performance composite materials could be obtained. Finally, nanocomposites allow using the semi-crystalline nature and hierarchical structure of lignocellulosic fibres and starch granules to more deeply achieve this goal profitably exploited by Mother Nature

  7. Environmentally friendly cellulose-based polyelectrolytes in wastewater treatment.

    Science.gov (United States)

    Grenda, Kinga; Arnold, Julien; Gamelas, José A F; Rasteiro, Maria G

    2017-09-01

    Natural-based polyelectrolytes (PELs), with all the advantages coming from being produced from renewable and biodegradable sources, are a potential solution for the removal of dyes from wastewater. In this work, surplus Eucalyptus bleached cellulose fibres from a paper mill were modified to increase the charge and solubility of cellulose. First, reactive aldehyde groups were introduced in the cellulose backbone by periodate oxidation of cellulose. Further modification with alkylammonium produced positively charged cellulose-based PELs. The final products were characterized by several analytical techniques. The PEL with the highest substitution degree of cationic groups was evaluated for its performance in decolouration processes, bentonite being used as aid. This was found to be effective for colour removal of either anionic or cationic dyes. Bio-PELs can thus be considered as very favourable eco-friendly flocculation agents for decolouration of harsh effluents from several industries, considering their biodegradable nature and thus the ability to produce less sludge.

  8. Regulation of cellulose synthesis in response to stress.

    Science.gov (United States)

    Kesten, Christopher; Menna, Alexandra; Sánchez-Rodríguez, Clara

    2017-12-01

    The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. High-strength cellulose/poly(ethylene glycol) gels.

    Science.gov (United States)

    Liang, Songmiao; Wu, Junjie; Tian, Huafeng; Zhang, Lina; Xu, Jian

    2008-01-01

    Cellulose gel membranes have been prepared by a pre-gelation method employing cellulose solutions in aqueous NaOH-thiourea obtained at low temperature. The cellulose gels were then swollen by low-molecular-weight polyethylene glycol (PEG; MWcellulose/PEG gels were studied by various techniques. The gels exhibit high mechanical performance, and the tensile strength of the gel membranes increases sharply with an increase in the molecular weight of PEG from 200 to 800 g mol(-1). Moreover, their elongation at break remains stable at 100 %. PEG800 efficiently improves the optical transmittance of the gel membranes at ambient temperature, which is about five times greater than that of a normal cellulose hydrogel membrane. A strong hydrogen-bonding interaction occurs between PEG and cellulose leading to a homogeneous structure, high mechanical strength and good transparency of the gel membranes.

  10. Evaluation of supercritical CO2 dried cellulose aerogels as nano-biomaterials

    Science.gov (United States)

    Lee, Sinah; Kang, Kyu-Young; Jeong, Myung-Joon; Potthast, Antje; Liebner, Falk

    2017-10-01

    Cellulose is the renewable, biodegradable and abundant resource and is suggested as an alternative material to silica due to the high price and environmental load of silica. The first step for cellulose aerogel production is to dissolve cellulose, and hydrated calcium thiocyanate molten salt is one of the most effective solvents for preparing porous material. Cellulose aerogels were prepared from dissolved cellulose samples of different degree of polymerization (DP) and drying methods, and tested with shrinkage, density and mechanical strength. Supercritical CO2 dried cellulose aerogels shrank less compared to freeze-dried cellulose aerogels, whereas the densities were increased according to the DP increases in both cellulose aerogels. Furthermore, scanning electron microscope (SEM) images showed that the higher DP cellulose aerogels were more uniform with micro-porous structure. Regarding the mechanical strength of cellulose aerogels, supercritical CO2 dried cellulose aerogels with higher molecular weight were much more solid.

  11. Directional Freezing of Nanocellulose Dispersions Aligns the Rod-Like Particles and Produces Low-Density and Robust Particle Networks.

    Science.gov (United States)

    Munier, Pierre; Gordeyeva, Korneliya; Bergström, Lennart; Fall, Andreas B

    2016-05-09

    We show that unidirectional freezing of nanocellulose dispersions produces cellular foams with high alignment of the rod-like nanoparticles in the freezing direction. Quantification of the alignment in the long direction of the tubular pores with X-ray diffraction shows high orientation of cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC) at particle concentrations above 0.2 wt % (CNC) and 0.08 wt % (CNF). Aggregation of CNF by pH decrease or addition of salt significantly reduces the particle orientation; in contrast, exceeding the concentration where particles gel by mobility constraints had a relatively small effect on the orientation. The dense nanocellulose network formed by directional freezing was sufficiently strong to resist melting. The formed hydrogels were birefringent and displayed anisotropic laser diffraction patterns, suggesting preserved nanocellulose alignment and cellular structure. Nondirectional freezing of the hydrogels followed by sublimation generates foams with a pore structure and nanocellulose alignment resembling the structure of the initial directional freezing.

  12. Hunting particles

    International Nuclear Information System (INIS)

    Southworth, B.; Boixader, G.

    1978-09-01

    The authors provide a general introduction to elementary particle physics and the work of CERN. This introduction is aimed at the young reader and uses cartoons to explain how elementary particles behave and how they are studied in the CERN accelerators. The purpose and administration of CERN is also briefly summarized. (W.D.L.)

  13. Direct pelletization in a rotary processor controlled by torque measurements. III. Investigation of microcrystalline cellulose and lactose grade.

    Science.gov (United States)

    Kristensen, Jakob

    2005-10-24

    The aim of the present study was to investigate the use of different grades of microcrystalline cellulose (MCC) and lactose in a direct pelletization process in a rotary processor. For this purpose, a mixed 2- and 3-level factorial study was performed to determine the influence of the particle size of microcrystalline cellulose (MCC) (approximately 60 and 105 microm) and lactose (approximately 30, 40, and 55 microm), as well as MCC type (Avicel and Emcocel) on the pelletization process and the physical properties of the prepared pellets. A 1:4 mixture of MCC and lactose was applied, and granulation liquid was added until a 0.45 Nm increase in the torque of the friction plate was reached. All combinations of the 3 factors resulted in spherical pellets of a high physical strength. The particle size of MCC was found to have no marked effect on the amount of water required for agglomerate growth or on the size of the resulting pellets. An increasing particle size of lactose gave rise to more spherical pellets of a more narrow size distribution as well as higher yields. The MCC type was found to affect both the release of the model drug from the prepared pellets and the size distribution. Generally, the determined influence of the investigated factors was small, and direct pelletization in a rotary processor was found to be a robust process, insensitive to variations in the particle size and type of MCC and the particle size of lactose.

  14. Radiation induced crosslinking of cellulose ethers

    International Nuclear Information System (INIS)

    Wach, A.R.; Mitomo, H.; Yoshii, F.; Kume, T.

    2002-01-01

    The effects of high-energy radiation on four ethers of cellulose: carboxymethyl (CMC); hydroxypropyl (HPC), hydroxyethyl (HEC) and methylcellulose (MC) were investigated. Polymers are irradiated in solid state and in aqueous solutions at various concentrations. Degree of substitution (DS) of the derivatives, the concentration of their aqueous solutions and irradiation conditions had a significant impact on the obtained products. Irradiation of polymers in solid state and in diluted aqueous solutions resulted in their degradation. However, it was found that for concentrated solutions gel formation occurred. Paste-like form of the initial material, when water plasticizes the bulk of polymer as well as the high dose rate, what prevents oxygen penetration of the polymer during irradiation, have been found favourable for hydrogel formation. Up to 95% of gel fraction was obtained from solutions of CMC with concentration over 50% irradiated by γ-rays or electron beam. It was pointed out that the ability to the formation of the three-dimensional network is related to the DS of anhydroglucose units and a type of chemical group introduced to main chain of cellulose. Produced hydrogels swelled markedly in water. Despite of the crosslinked structure they underwent degradation by the action of cellulase enzyme or microorganisms from compost, and can be included into the group of biodegradable materials. (author)

  15. Extensional viscosity of microfibrillated cellulose suspensions.

    Science.gov (United States)

    Moberg, Tobias; Rigdahl, Mikael; Stading, Mats; Levenstam Bragd, Emma

    2014-02-15

    The extensional properties of micro fibrillated cellulose (MFC)-suspensions at different fibril concentrations and with different amounts of added sodium chloride were evaluated. The MFC-suspensions were obtained by diluting a stock solution consisting of 0.95 wt.% cellulose with either deionized water or sodium chloride solution, giving a series of different concentrations and sodium chloride contents. The extensional viscosities of the suspensions were measured utilizing contraction flow geometry. Here the specimens were forced through a hyperbolic nozzle and the required pressure drop over the nozzle was measured. The extensional viscosity exhibited an extensional-thinning behaviour over the extensional strain rates used. Furthermore the extensional viscosity decreased with decreasing concentration of the suspensions, in similarities with the shear properties of the specimens. For the suspensions containing sodium chloride, the extensional viscosity appeared to increase when the concentration of sodium chloride was increased. But excessive amounts of added sodium chloride promoted an agglomeration of the suspensions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Films prepared from electrosterically stabilized nanocrystalline cellulose.

    Science.gov (United States)

    Yang, Han; Tejado, Alvaro; Alam, Nur; Antal, Miro; van de Ven, Theo G M

    2012-05-22

    Electrosterically stabilized nanocrystalline cellulose (ENCC) was modified in three ways: (1) the hydroxyl groups on C2 and C3 of glucose repeat units of ENCC were converted to aldehyde groups by periodate oxidation to various extents; (2) the carboxyl groups in the sodium form on ENCC were converted to the acid form by treating them with an acid-type ion-exchange resin; and (3) ENCC was cross-linked in two different ways by employing adipic dihydrazide as a cross-linker and water-soluble 1-ethyl-3-[3-(dimethylaminopropyl)] carbodiimide as a carboxyl-activating agent. Films were prepared from these modified ENCC suspensions by vacuum filtration. The effects of these three modifications on the properties of films were investigated by a variety of techniques, including UV-visible spectroscopy, a tensile test, thermogravimetric analysis (TGA), the water vapor transmission rate (WVTR), and contact angle (CA) studies. On the basis of the results from UV spectra, the transmittance of these films was as high as 87%, which shows them to be highly transparent. The tensile strength of these films was increased with increasing aldehyde content. From TGA and WVTR experiments, cross-linked films showed much higher thermal stability and lower water permeability. Furthermore, although the original cellulose is hydrophilic, these films also exhibited a certain hydrophobic behavior. Films treated by trichloromethylsilane become superhydrophobic. The unique characteristics of these transparent films are very promising for potential applications in flexible packaging and other high-technology products.

  17. Anaerobic digestion of cellulosic wastes: laboratory tests

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1984-11-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 10 references, 17 figures, 4 tables

  18. Communication and Sensing Circuits on Cellulose

    Directory of Open Access Journals (Sweden)

    Federico Alimenti

    2015-06-01

    Full Text Available This paper proposes a review of several circuits for communication and wireless sensing applications implemented on cellulose-based materials. These circuits have been developed during the last years exploiting the adhesive copper laminate method. Such a technique relies on a copper adhesive tape that is shaped by a photo-lithographic process and then transferred to the hosting substrate (i.e., paper by means of a sacrificial layer. The presented circuits span from UHF oscillators to a mixer working at 24 GHz and constitute an almost complete set of building blocks that can be applied to a huge variety communication apparatuses. Each circuit is validated experimentally showing performance comparable with the state-of-the-art. This paper demonstrates that circuits on cellulose are capable of operating at record frequencies and that ultra- low cost, green i.e., recyclable and biodegradable materials can be a viable solution to realize high frequency hardware for the upcoming Internet of Things (IoT era.

  19. Bifunctional dendronized cellulose surfaces as biosensors.

    Science.gov (United States)

    Montanez, Maria I; Hed, Yvonne; Utsel, Simon; Ropponen, Jarmo; Malmstrom, Eva; Wagberg, Lars; Hult, Anders; Malkoch, Michael

    2011-06-13

    Well-defined dendronized cellulose substrates displaying multiple representations of dual-functionality were constructed by taking advantage of the efficiency of the click reaction combined with traditional anhydride chemistry. First, activated cellulose surfaces were decorated with several generations of dendrons, and their peripheral reactive groups were subsequently reacted with a trifunctional orthogonal monomer. The generated substrate tool box was successfully explored by accurately tuning the surface function using a versatile orthogonal dual postfunctionalization approach. In general, the reactions were monitored by using a click-dye reagent or a quartz crystal microbalance (QCM) technique, and the resulting surfaces were well-characterized using XPS, FT-IR, and contact angle measurements. Utilizing this approach two different surfaces have been obtained; that is, triethylenglycol oligomers and amoxicillin molecules were efficiently introduced to the dendritic surface. As a second example, mannose-decorated hydroxyl functional surfaces illustrated their potential as biosensors by multivalent detection of lectin protein at concentration as low as 5 nM.

  20. Preparation of Photoresponsive Functionalized Acrylic Nanoparticles Cantaining Carbazole Groups for Smart Cellulosic Papers

    Directory of Open Access Journals (Sweden)

    Jaber Keyvan Rad

    2017-11-01

    Full Text Available Photoresponsive functionalized polymer nanoparticles were prepared as useful materials for preparation of smart papers. Such polymer nanoparticles have wide applications in several fields including papers, sensors, bioimaging and biomedicine. First, carbazole as a photosensitive compound was modified with 2-bromoethanol through substitution nucleation reaction to its hydroxyl derivative (N-(2-hydroxyethyl carbazole, CzEtOH. The synthesis of 2-N-carbazolylethyl acrylate (CzEtA monomer was carried out by modification reaction of CzEtOH with acryloyl chloride and the chemical structures of the products were characterized. Next, CzEtA, methyl methacrylate (MMA and butyl acrylate were copolymerized to prepare photoresponsive functionalized polymer nanoparticles through mini-emulsion polymerization in order to form a hydrophobic core. This was followed by copolymerization of MMA and glycidyl methacrylate by seeded emulsion polymerization to give a functionalized outer layer on the latex particles. Absorption characteristics, size, size distribution (narrow size distribution and morphology of the nanoparticles were studied by ultraviolet-visible (UV-Vis spectroscopy, dynamic laser light scattering (DLS analysis and scanning electron microscopy (SEM micrographs, respectively. Finally, due to the importance of photoresponsive smart papers and their wide applications, cellulosic fibers were reacted with the prepared functionalized latex particles for preparation of smart papers. Morphology of the fibers was investigated with respect to the surface-immobilized polymers on the cellulosic paper and their smart behavior was evaluated by UV irradiation at 254 nm. The results revealed fast color changes and the obtained cellulosic papers became violet upon irradiation. This work shows some promising feature of these materials for preparation of anti-counterfeiting papers, where the safety becomes a major concern.

  1. Studying the Improvement of the Solubility of Cellulosic Fibers

    Directory of Open Access Journals (Sweden)

    Asem Hassan Mohammed

    2016-07-01

    Full Text Available This study focuses for improving the increase the solubility of fiber cellulose in sodium hydroxide solution in concentrations ranging from (4- 12%, from one point of view and from other point of view in (sodium hydroxide and urea solution concentration (6% NaOH + 4% urea, under low temperature (- 15, - 20 Co , depending on the principle of reducing the degree of polymerization for fiber cellulose, which is represented in our tests cotton linter who its represent (Whatman filter paper, Grade 1, some samples subjected to chemical pretreatment as simulation the method of decomposition of cellulosic materials by white or brown fungi that grow on trees, this method involves the use of chemical materials, including hydrogen peroxide (H2O2 , oxalic acid C2H2O4 and ferrous sulfate FeSO4 to be reaction known ( Fenton reaction or Fenton's reagent which produce free radicals helps the decomposition of cellulose fibers. The results were as follows: The solubility of cellulose fiber in sodium hydroxide solution was up to 42% cellulose and the best sodium hydroxide concentration is 8% for treated simples in Fenton solution and for untreated simples were the best solubility of cellulose fiber up to 28% and the best temperature is -20 Co for both. For the solubility of cellulose fibers in sodium hydroxide and urea solution (6% NaOH + 4% urea was more than 60% of treated cellulose in Fenton reaction , while for untreated cellulose was the best solubility ratio up to 35% and it was the best temperature - 15 Co

  2. Cellulose-hemicellulose interaction in wood secondary cell-wall

    Science.gov (United States)

    Zhang, Ning; Li, Shi; Xiong, Liming; Hong, Yu; Chen, Youping

    2015-12-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose.

  3. Cellulose-hemicellulose interaction in wood secondary cell-wall

    International Nuclear Information System (INIS)

    Zhang, Ning; Li, Shi; Hong, Yu; Chen, Youping; Xiong, Liming

    2015-01-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose. (paper)

  4. Particle accelerator

    International Nuclear Information System (INIS)

    Ress, R.I.

    1976-01-01

    Charged particles are entrained in a predetermined direction, independent of their polarity, in a circular orbit by a magnetic field rotating at high speed about an axis in a closed cylindrical or toroidal vessel. The field may be generated by a cylindrical laser structure, whose beam is polygonally reflected from the walls of an excited cavity centered on the axis, or by high-frequency energization of a set of electromagnets perpendicular to the axis. In the latter case, a separate magnetostatic axial field limits the orbital radius of the particles. These rotating and stationary magnetic fields may be generated centrally or by individual magnets peripherally spaced along its circular orbit. Chemical or nuclear reactions can be induced by collisions between the orbiting particles and an injected reactant, or by diverting high-speed particles from one doughnut into the path of counterrotating particles in an adjoining doughnut

  5. Preparation of cellulose II and III{sub I} films by allomorphic conversion of bacterial cellulose I pellicles

    Energy Technology Data Exchange (ETDEWEB)

    Faria-Tischer, Paula C.S., E-mail: paula.tischer@pq.cnpq.br [BioPol, Departamento de Química, UFPR, Cx. Postal 19081, 81531-980 Curitiba, PR (Brazil); Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000 Grenoble (France); CNRS, CERMAV, F-38000 Grenoble (France); UMR 5628 (LMGP), CNRS and Grenoble Institute of Technology, 3 Parvis Louis Néel, F-38016 Grenoble Cedex 1 (France); Tischer, Cesar A. [BioPol, Departamento de Química, UFPR, Cx. Postal 19081, 81531-980 Curitiba, PR (Brazil); Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000 Grenoble (France); CNRS, CERMAV, F-38000 Grenoble (France); CIME Nanotech, 3 Parvis Louis Néel, F-38016 Grenoble Cedex 1 (France); Heux, Laurent [Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000 Grenoble (France); CNRS, CERMAV, F-38000 Grenoble (France); Le Denmat, Simon; Picart, Catherine [UMR 5628 (LMGP), CNRS and Grenoble Institute of Technology, 3 Parvis Louis Néel, F-38016 Grenoble Cedex 1 (France); Sierakowski, Maria-R. [BioPol, Departamento de Química, UFPR, Cx. Postal 19081, 81531-980 Curitiba, PR (Brazil); and others

    2015-06-01

    The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and III{sub I} (Cel III{sub I}) have usually been studied using powder samples from plant or algal cellulose. In this work, the conversion of Cel I into Cel II and Cel III{sub I} was performed on bacterial cellulose films without any mechanical disruption. The surface texture of the films was observed by atomic force microscopy (AFM) and the morphology of the constituting cellulose ribbons, by transmission electron microscopy (TEM). The structural changes were characterized using solid-state NMR spectroscopy as well as X-ray and electron diffraction. The allomorphic change into Cel II and Cel III{sub I} resulted in films with different crystallinity, roughness and hydrophobic/hydrophilicity surface and the films remained intact during all process of allomorphic conversion. - Highlights: • Description of a method to modify the allomorphic structure of bacterial cellulose films • Preparation of films with specific morphologies and hydrophobic/hydrophilic surface characters • First report on cellulose III films from bacterial cellulose under swelling conditions • Detailed characterization of cellulose II and III films with complementary techniques • Development of films with specific properties as potential support for cells, enzymes, and drugs.

  6. Integrated production of nano-fibrillated cellulose and cellulosic biofuel (ethanol) by enzymatic fractionation of wood fibers

    Science.gov (United States)

    Junyong Zhu; Ronald Sabo; Xiaolin Luo

    2011-01-01

    This study demonstrates the feasibility of integrating the production of nano-fibrillated cellulose (NFC), a potentially highly valuable biomaterial, with sugar/biofuel (ethanol) from wood fibers. Commercial cellulase enzymes were used to fractionate the less recalcitrant amorphous cellulose from a bleached Kraft eucalyptus pulp, resulting in a highly crystalline and...

  7. Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

    Science.gov (United States)

    Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

    2016-11-01

    Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

  8. Enzymic modification of cellulose - xyloglucan networks : implications for fruit juice processing = Enzymatische modificatie van cellulose - xyloglucaan netwerken

    NARCIS (Netherlands)

    Vincken, J.P.

    1996-01-01


    Xyloglucans play an important role in connecting cellulose microfibrils in the primary coli wall of plants, and the resulting cellulose-xyloglucan network is thought to determine the strength of these walls. Xyloglucans were isolated from apple fruit and potato tuber cell wall material by

  9. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    Directory of Open Access Journals (Sweden)

    Bojanić Vaso

    2010-01-01

    Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

  10. Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

    Directory of Open Access Journals (Sweden)

    Airong Xu

    2015-01-01

    Full Text Available Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose.

  11. X-ray photoelectron spectroscopy and infra-red studies of x-ray-induced beam damage of cellulose, ethyl cellulose and ethyl-hydroxyethyl cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.M.D.; Hewitt, J.A.; Meenan, B.J. (Ulster Univ., Coleraine (United Kingdom))

    1992-03-01

    The cellulose derivatives ethyl cellulose and ethyl-hydroxyethyl cellulose (EHEC) have been studied by XPS in the form of solvent-cast films. All the films, as well as a sample of cellulose used as a standard material, show significant surface degradation on irradiation in the time period consistent with XPS data acquisition. Under the experimental conditions employed here the four materials studied behave similarly, in that a reaction occurs in the cellulose skeleton, resulting in dehydroxylation of some of the pyranose units in the surface layers, with concomitant elimination of molecules of water. An infrared (IR) analysis of the ethyl cellulose and high-molecular-weight EHEC films indicates the presence of a strong carbonyl band, no evidence for which is found in the XPS spectra. However, other features of the IR spectra support the proposed dehydroxylation mechanism. The origin of this inconsistency is unclear but may be attributable to either differences in the surface and bulk degradation products formed or to the detection differences of the XPS and IR techniques. (author).

  12. Synthesis and characterization of cellulose whiskers/polymer nanocomposite dispersion by mini-emulsion polymerization.

    Science.gov (United States)

    Ben Mabrouk, Ayman; Rei Vilar, Manuel; Magnin, Albert; Belgacem, Mohamed Naceur; Boufi, Sami

    2011-11-01

    Stable film-forming nanocomposite particles with diameters ranging from 120 to 300 nm, based on polybutylmethacrylate (PBMA) and cellulose whiskers in water dispersions, were successfully synthesized in one step through mini-emulsion polymerization. The nanocomposite dispersion with a solid content of 25 wt.% and up to 5 wt.% of nanofiller loading was prepared by in situ polymerization, in the presence of the whiskers using dodecylpyridinium chloride (DPC), as a cationic surfactant, and 2,2-azobis(isobutyronitrile) (AIBN), as initiator. The electrostatic interaction between the positively charged droplets and negatively charged whiskers ensured the anchoring of the nanofiller around the polymer particles. The ensuing dispersions were characterized by Dynamic Light Scattering (DLS), ζ-Potential Measurements, and Field-Emission Scanning Electron Microscopy (FE-SEM). After the film formation process, the nanocomposite film exhibits a high transparency, denoting the good dispersion of the whiskers throughout the matrix. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Simple preparation of Fenton catalyst@bacterial cellulose for waste water treatment

    Science.gov (United States)

    Wibowo, Arie; Febi Indrawan, Radian; Triadhi, Untung; Hasdi Aimon, Akfiny; Iskandar, Ferry; Ardy, Husaini

    2018-02-01

    Heterogeneous fenton catalyst is one of the attractive technologies for destruction of persistent and non-biodegradable pollutant in wastewater, because it can be used in wide range of pH and recyclable. Herein, commercial bacterial celluloses (BCs) were used as an alternative support of fenton catalyst to improve their catalytic activity. Scanning Electron Microscope (SEM) observations indicated that the presence of BCs and decreasing precursor concentration might promote formation of smaller particle sizes of catalyst from 3.5 μm of bare catalyst to 0.7 μm of catalyst@BC. UV-vis measurement showed that fast degradation of dyes with half-time degradation at around 25 min was observed in sample using catalyst@BCs with precursor concentration of 0.01 M. Successful preparation of heterogeneous fenton catalyst with smaller particle size and better catalytic activity is important for their application in wastewater treatment.

  14. Particle separation

    International Nuclear Information System (INIS)

    Baker, C.A.

    1990-01-01

    Solid particles are separated from a liquid which also contains ferric hydroxide by subjecting the liquid to ultrasonic agitation from a transducer in order to break up the flocs so that they will pass with the liquid through a filter belt. The belt thus retains the solid particles without interference from the flocs. As shown the woven nylon belt collects rare radioactive solid particles from liquid and carries them under sensors. The belt is washed clean, with further ultrasonic agitation in a trough on its return run. (author)

  15. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hyeun Jong; Wi, Seung Gon; Lee, Yoon Gyo; Kim, Ho Myung; Kim, Su Bae [Chonnam National University, Gwangju (Korea, Republic of)

    2011-10-15

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. The 2nd year Research scope includes: 1) Optimization of pre-treatment conditions for enzymatic hydrolysis of lignocellulosic biomass and 2) Demonstration of enzymatic hydrolysis by recombinant enzymes. To optimize the pretreatment, we applied two processes: a wet process (wet milling + popping), and dry process (popping + dry milling). Out of these, the wet process presented the best glucose yield with a 93.1% conversion, while the dry process yielded 69.6%, and the unpretreated process yielded <20%. The recombinant cellulolytic enzymes showed very high specific activity, about 80-1000 times on CMC and 13-70 times on filter paper at pH 3.5 and 55 .deg. C

  16. Preparation and characterization of nanocomposites of the carboxymethyl cellulose reinforced with cellulose nanocrystals

    International Nuclear Information System (INIS)

    Flauzino Neto, Wilson P.; Silverio, Hudson A.; Vieira, Julia G.; Silva, Heden C.; Rosa, Joyce R.; Pasquini, Daniel; Assuncao, Rosana M.N.

    2011-01-01

    Nanocrystals of cellulose (NCC) isolated from Eucalyptus urograndis Kraft pulp were used to prepare nanocomposites employing carboxymethyl cellulose (CMC) as matrix. The nanocrystals were isolated by hydrolysis with H 2 SO 4 64% solution, for 20 minutes at 45 deg C. The nanocrystals were characterized by X-ray diffraction to evaluate the crystallinity of them. The amount of NCC used in the preparation of nanocomposites varied from 0 to 15%. The nanocomposites were characterized by thermal and mechanical analysis. A large reinforcing effect of NCC on the CMC matrix was observed. With the incorporation of the NCC, the tensile strength of nanocomposites was significantly improved by 107%, the elongation at break decreased by 48% and heat resistance to decomposition increased subtle. The improvement in thermo-mechanical properties are attributed to strong interactions between nanoparticles and CMC matrix. (author)

  17. The microwave assisted-synthesis of carboxymethyl cellulose from nata de-coco bacterial cellulose

    Science.gov (United States)

    Ramadhan, L. O. A. N.; Nur Rahmat, M.; Susilowati, P. E.; Ahmad, L. O.; Edy Rusbandi, U.

    2017-07-01

    Bacterial cellulose (BC) is one of natural biopolymers which can be derivatized to make functionalized materials. Carboxymethyl cellulose (CMC) is a candidate derivative for such a direction. The aim of the present study is to investigate the usability of microwave energy to transform BC into CMC. The results showed that CMC was produced in a yellowish white powder by a short irradiation for 30 s at 650 W. The best combination of monochloroacetic acid and BC as anhydrogucose unit was found at the molar ratio of 1:5. The obtained CMC is soluble in distilled water, and aqueous NaOH solution. The highest degree of substitution, viscosity, and molecular weight of the CMC are 0.263, 15.61 Pa·s and 197,187, respectively. This study showed the usefulness of the microwave-assisted reaction to transform BC rapidly into water-soluble ionized derivative.

  18. Advances in cellulosic conversion to fuels: engineering yeasts for cellulosic bioethanol and biodiesel production.

    Science.gov (United States)

    Ko, Ja Kyong; Lee, Sun-Mi

    2018-04-01

    Cellulosic fuels are expected to have great potential industrial applications in the near future, but they still face technical challenges to become cost-competitive fuels, thus presenting many opportunities for improvement. The economical production of viable biofuels requires metabolic engineering of microbial platforms to convert cellulosic biomass into biofuels with high titers and yields. Fortunately, integrating traditional and novel engineering strategies with advanced engineering toolboxes has allowed the development of more robust microbial platforms, thus expanding substrate ranges. This review highlights recent trends in the metabolic engineering of microbial platforms, such as the industrial yeasts Saccharomyces cerevisiae and Yarrowia lipolytica, for the production of renewable fuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Bacterial Cellulose Ionogels as Chemosensory Supports.

    Science.gov (United States)

    Smith, Chip J; Wagle, Durgesh V; O'Neill, Hugh M; Evans, Barbara R; Baker, Sheila N; Baker, Gary A

    2017-11-01

    To fully leverage the advantages of ionic liquids for many applications, it is necessary to immobilize or encapsulate the fluids within an inert, robust, quasi-solid-state format that does not disrupt their many desirable, inherent features. The formation of ionogels represents a promising approach; however, many earlier approaches suffer from solvent/matrix incompatibility, optical opacity, embrittlement, matrix-limited thermal stability, and/or inadequate ionic liquid loading. We offer a solution to these limitations by demonstrating a straightforward and effective strategy toward flexible and durable ionogels comprising bacterial cellulose supports hosting in excess of 99% ionic liquid by total weight. Termed bacterial cellulose ionogels (BCIGs), these gels are prepared using a facile solvent-exchange process equally amenable to water-miscible and water-immiscible ionic liquids. A suite of characterization tools were used to study the preliminary (thermo)physical and structural properties of BCIGs, including no-deuterium nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction. Our analyses reveal that the weblike structure and high crystallinity of the host bacterial cellulose microfibrils are retained within the BCIG. Notably, not only can BCIGs be tailored in terms of shape, thickness, and choice of ionic liquid, they can also be designed to host virtually any desired active, functional species, including fluorescent probes, nanoparticles (e.g., quantum dots, carbon nanotubes), and gas-capture reagents. In this paper, we also present results for fluorescent designer BCIG chemosensor films responsive to ammonia or hydrogen sulfide vapors on the basis of incorporating selective fluorogenic probes within the ionogels. Additionally, a thermometric BCIG hosting the excimer-forming fluorophore 1,3-bis(1-pyrenyl)propane was devised which exhibited a ratiometric (two

  20. Microbial fuel cells using Cellulomonas spp. with cellulose as fuel.

    Science.gov (United States)

    Takeuchi, Yuya; Khawdas, Wichean; Aso, Yuji; Ohara, Hitomi

    2017-03-01

    Cellulomonas fimi, Cellulomonas biazotea, and Cellulomonas flavigena are cellulose-degrading microorganisms chosen to compare the degradation of cellulose. C. fimi degraded 2.5 g/L of cellulose within 4 days, which was the highest quantity among the three microorganisms. The electric current generation by the microbial fuel cell (MFC) using the cellulose-containing medium with C. fimi was measured over 7 days. The medium in the MFC was sampled every 24 h to quantify the degradation of cellulose, and the results showed that the electric current increased with the degradation of cellulose. The maximum electric power generated by the MFC was 38.7 mW/m 2 , and this numeric value was 63% of the electric power generated by an MFC with Shewanella oneidensis MR-1, a well-known current-generating microorganism. Our results showed that C. fimi was an excellent candidate to produce the electric current from cellulose via MFCs. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. Cellulosic Bionanocomposites: A Review of Preparation, Properties and Applications

    Directory of Open Access Journals (Sweden)

    Alain Dufresne

    2010-12-01

    Full Text Available Cellulose is the most abundant biomass material in nature. Extracted from natural fibers, its hierarchical and multi-level organization allows different kinds of nanoscaled cellulosic fillers—called cellulose nanocrystals or microfibrillated cellulose (MFC—to be obtained. Recently, such cellulose nanoparticles have been the focus of an exponentially increasing number of works or reviews devoted to understanding such materials and their applications. Major studies over the last decades have shown that cellulose nanoparticles could be used as fillers to improve mechanical and barrier properties of biocomposites. Their use for industrial packaging is being investigated, with continuous studies to find innovative solutions for efficient and sustainable systems. Processing is more and more important and different systems are detailed in this paper depending on the polymer solubility, i.e., (i hydrosoluble systems, (ii non-hydrosoluble systems, and (iii emulsion systems. This paper intends to give a clear overview of cellulose nanoparticles reinforced composites with more than 150 references by describing their preparation, characterization, properties and applications.

  2. Cellulose based hybrid hydroxylated adducts for polyurethane foams

    Science.gov (United States)

    De Pisapia, Laura; Verdolotti, Letizia; Di Mauro, Eduardo; Di Maio, Ernesto; Lavorgna, Marino; Iannace, Salvatore

    2012-07-01

    Hybrid flexible polyurethane foams (HPU) were synthesized by using a hybrid hydroxilated adduct (HHA) based on renewable resources. In particular the HHA was obtained by dispersing cellulose wastes in colloidal silica at room temperature, pressure and humidity. The colloidal silica was selected for its ability of modifying the cellulose structure, by inducing a certain "destructurization" of the crystalline phase, in order to allow cellulose to react with di-isocyanate for the final synthesis of the polyurethane foam. In fact, cellulose-polysilicate complexes are engaged in the reaction with the isocyanate groups. This study provides evidence of the effects of the colloidal silica on the cellulose structure, namely, a reduction of the microfiber cellulose diameter and the formation of hydrogen bonds between the polysilicate functional groups and the hydroxyl groups of the cellulose, as assessed by IR spectroscopy and solid state NMR. The HHA was added to a conventional polyol in different percentages (between 5 and 20%) to synthesize HPU in presence of catalysts, silicone surfactant and diphenylmethane diisocyanate (MDI). The mixture was expanded in a mold and cured for two hours at room temperature. Thermal analysis, optical microscopy and mechanical tests were performed on the foams. The results highlighted an improvement of thermal stability and a decrease of the cell size with respect neat polyurethane foam. Mechanical tests showed an improvement of the elastic modulus and of the damping properties with increasing HHA amount.

  3. Extraction and characterisation of cellulose nanocrystals from pineapple peel

    Directory of Open Access Journals (Sweden)

    Ana Raquel Madureira

    2018-04-01

    Full Text Available The potential of pineapple peel as a source of cellulose nanocrystals was evaluated. Peels skin from fresh-cut fruit was used as raw material. These residues were purified to remove pigments, lipids and hemicellulose, and a bleaching process for delignification was carried out for 4-6 h. All resulting products were characterised for their lignin, hemicellulose, cellulose and ash contents using standard techniques. Dry matter at the end was low (ca. 50% compared with the raw material (ca. 90%. The process applied resulted in ca. 20% (m/m of purified cellulose (ca. 80% purity, with ineligible levels of lignin and hemicellulose present, especially when using 6h of bleaching. The purified cellulose was subject to acid hydrolysis for nanocrystal extraction with two testing times, 30 and 60 minutes. These cellulose nanocrystals had small sizes (< 1000 nm, with high variability and negative zeta potential values. The time of extraction did not affect the nanocrystals’ chemical and physical properties. The use of 6 h of bleaching treatment during purification was shown to be more effective than 4 h. Pineapple peel was demonstrated to be a good source of cellulose for the production of cellulose nanocrystals.

  4. Cellulose Supplementation Early in Life Ameliorates Colitis in Adult Mice

    Science.gov (United States)

    Nagy-Szakal, Dorottya; Hollister, Emily B.; Luna, Ruth Ann; Szigeti, Reka; Tatevian, Nina; Smith, C. Wayne; Versalovic, James; Kellermayer, Richard

    2013-01-01

    Decreased consumption of dietary fibers, such as cellulose, has been proposed to promote the emergence of inflammatory bowel diseases (IBD: Crohn disease [CD] and ulcerative colitis [UC]) where intestinal microbes are recognized to play an etiologic role. However, it is not known if transient fiber consumption during critical developmental periods may prevent consecutive intestinal inflammation. The incidence of IBD peaks in young adulthood indicating that pediatric environmental exposures may be important in the etiology of this disease group. We studied the effects of transient dietary cellulose supplementation on dextran sulfate sodium (DSS) colitis susceptibility during the pediatric period in mice. Cellulose supplementation stimulated substantial shifts in the colonic mucosal microbiome. Several bacterial taxa decreased in relative abundance (e.g., Coriobacteriaceae [p = 0.001]), and other taxa increased in abundance (e.g., Peptostreptococcaceae [p = 0.008] and Clostridiaceae [p = 0.048]). Some of these shifts persisted for 10 days following the cessation of cellulose supplementation. The changes in the gut microbiome were associated with transient trophic and anticolitic effects 10 days following the cessation of a cellulose-enriched diet, but these changes diminished by 40 days following reversal to a low cellulose diet. These findings emphasize the transient protective effect of dietary cellulose in the mammalian large bowel and highlight the potential role of dietary fibers in amelioration of intestinal inflammation. PMID:23437211

  5. Bacterial cellulose biosynthesis: diversity of operons, subunits, products and functions

    Science.gov (United States)

    Römling, Ute; Galperin, Michael Y.

    2015-01-01

    Summary Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits – which differ among various taxa – affect the enzymatic activity and product yield in vivo by modulating expression of biosynthesis apparatus, export of the nascent β-D-glucan polymer to the cell surface, and the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of the resulting biofilm, which is particularly important for interactions of bacteria with higher organisms that lead to rhizosphere colonization and modulate virulence of cellulose-producing bacterial pathogens inside and outside of host cells. Here we review the organization of four principal types of cellulose synthase operons found in various bacterial genomes, identify additional bcs genes that encode likely components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms formed by a variety of free-living and pathogenic bacteria and, for the latter, in the choice between acute infection and persistence in the host. PMID:26077867

  6. Smart Cellulose Fibers Coated with Carbon Nanotube Networks

    Directory of Open Access Journals (Sweden)

    Haisong Qi

    2014-11-01

    Full Text Available Smart multi-walled carbon nanotube (MWCNT-coated cellulose fibers with a unique sensing ability were manufactured by a simple dip coating process. The formation of electrically-conducting MWCNT networks on cellulose mono- and multi-filament fiber surfaces was confirmed by electrical resistance measurements and visualized by scanning electron microscopy. The interaction between MWCNT networks and cellulose fiber was investigated by Raman spectroscopy. The piezoresistivity of these fibers for strain sensing was investigated. The MWCNT-coated cellulose fibers exhibited a unique linear strain-dependent electrical resistance change up to 18% strain, with good reversibility and repeatability. In addition, the sensing behavior of these fibers to volatile molecules (including vapors of methanol, ethanol, acetone, chloroform and tetrahydrofuran was investigated. The results revealed a rapid response, high sensitivity and good reproducibility for these chemical vapors. Besides, they showed good selectivity to different vapors. It is suggested that the intrinsic physical and chemical features of cellulose fiber, well-formed MWCNT networks and favorable MWCNT-cellulose interaction caused the unique and excellent sensing ability of the MWCNT-coated cellulose fibers, which have the potential to be used as smart materials.

  7. Chitosan Based Regenerated Cellulose Fibers Functionalized with Plasma and Ultrasound

    Directory of Open Access Journals (Sweden)

    Urška Vrabič Brodnjak

    2018-04-01

    Full Text Available The great potential of regenerated cellulose fibers, which offer excellent possibilities as a matrix for the design of bioactive materials, was the lead for our research. We focused on the surface modification of fibers to improve the sorption properties of regenerated cellulose and biocomposite regenerated cellulose/chitosan fibers, which are on the market. The purpose of our investigation was also the modification of regenerated cellulose fibers with the functionalization by chitosan as a means of obtaining similar properties to biocomposite regenerated cellulose/chitosan fibers on the market. Argon gas plasma was used for fiber surface activation and chitosan adsorption. Ultrasound was also used as a treatment procedure for the surface activation of regenerated cellulose fibers and treatment with chitosan. Analyses have shown that ultrasonic energy or plasma change the accessibility of free functional groups, structure and reactivity, especially in regenerated cellulose fibers. Changes that occurred in the morphology and in the structure of fibers were also reflected in their physical and chemical properties. Consequently, moisture content, sorption properties and water retention improved.

  8. Obtaining of Peracetic Cellulose from Oat Straw for Paper Manufacturing

    Directory of Open Access Journals (Sweden)

    Tetyana V. Zelenchuk

    2017-10-01

    Full Text Available Background. Development of technology for obtaining peracetic pulp from oat straw and its use in the production of one of the paper mass types. Objective. Determination of peracetic cooking technological parameters’ optimal values for oat straw peracetic cellulose quality indicators. Methods. The oat straw cooking was carried out with peracetic acid at 95 ± 1 °C from 90 to 180 min for hydromodulus 8:1 and 7:1, using a sodium tungstate catalyst. To determine the oat straw peracetic cellulose mechanical indexes, laboratory samples of paper weighing 70 g/m2 were made. Results. Technological parameters’ optimum values (temperature, cooking duration, hydromodulus, hydrogen peroxide and acetic acid concentration for the oat straw delignification process were established. It is shown that the sodium tungstate catalyst addition to the cooking solution at a rate of up to 1 % of the plant raw material weight helps to reduce the lignin content in cellulose to 15 %. A diagram of the cellulose yield dependence on its residual lignin content for various methods of non-wood plant material species delignification is constructed. The high efficiency of the peracetic method for obtaining cellulose from non-wood plant raw materials, in particular from oat straw, has been confirmed. It is determined that the obtained peracetic cellulose from oat straw has high mechanical indexes. Conclusions. Oat straw peracetic cellulose can be used for the production of paper and cardboard mass types, in particular wrapping paper.

  9. Enhanced cellulose degradation using cellulase-nanosphere complexes.

    Directory of Open Access Journals (Sweden)

    Craig Blanchette

    Full Text Available Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC; however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

  10. Removal of Cu²⁺ from aqueous solutions by the novel modified bagasse pulp cellulose: Kinetics, isotherm and mechanism.

    Science.gov (United States)

    Zhu, Hong-Xiang; Cao, Xue-Juan; He, Yu-Cai; Kong, Qiao-Ping; He, Hui; Wang, Jin

    2015-09-20

    This study designed and synthesized a novel cellulose-based heavy metal adsorption material. One kind of bagasse pulp cellulose was pretreated under microwave 200 W for 3 min before the epoxidation, amination and ultrasonic enhancement sulfonation reaction. Heavy metal adsorption groups N and S were grafted onto the bagasse pulp cellulose. Furthermore, the effects of solution pH, adsorption temperature, adsorbent dosage, Cu(2+) concentration, and adsorbent recycling on adsorption capacity were investigated. Under the optimum condition, the adsorption amount of Cu(2+) was 35.2mg/g adsorbent. Compared with other cellulose-based adsorbents, this kind of adsorbent could be easily prepared and effectively recycled. Except for the normal fitting of adsorption process with the Langmuir isotherm adsorption model, Freundlich isotherm adsorption model and secondary adsorption kinetics model, the solid-liquid phase adsorption mechanism was also introduced to explain the Cu(2+) adsorption process. Three consecutive stages were deeply discussed and verified, where the surface diffusion and particle internal diffusion process were the primary along with a quick adsorption of the adsorbate onto the in-hole surface of the cellulose-based adsorbent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Dental glass ionomer cement reinforced by cellulose microfibers and cellulose nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rafael M. [Departamento de Odontologia, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Centro Avançado de Avaliação e Desenvolvimento de Biomateriais, BioMat, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Pereira, Fabiano V., E-mail: fabianovp@ufmg.br [Departamento de Química, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte CEP: 31270-901, MG (Brazil); Mota, Felipe A.P. [Centro Avançado de Avaliação e Desenvolvimento de Biomateriais, BioMat, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Watanabe, Evandro [Departamento de Odontologia Restauradora, Faculdade de Odontologia de Ribeirão Preto, USP, Ribeirão Preto CEP: 14040-904, SP (Brazil); Soares, Suelleng M.C.S. [Departamento de Odontologia, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Santos, Maria Helena [Departamento de Odontologia, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Centro Avançado de Avaliação e Desenvolvimento de Biomateriais, BioMat, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil)

    2016-01-01

    The aim of this work was to evaluate if the addition of cellulose microfibers (CmF) or cellulose nanocrystals (CNC) would improve the mechanical properties of a commercial dental glass ionomer cement (GIC). Different amounts of CmF and CNC were previously prepared and then added to reinforce the GIC matrix while it was being manipulated. Test specimens with various concentrations of CmF or CNC in their total masses were fabricated and submitted to mechanical tests (to evaluate their compressive and diametral tensile strength, modulus, surface microhardness and wear resistance) and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The incorporation of CmF in the GIC matrix did not greatly improve the mechanical properties of GIC. However, the addition of a small amount of CNC in the GIC led to significant improvements in all of the mechanical properties evaluated: compressive strength (increased up to 110% compared with the control group), elastic modulus increased by 161%, diametral tensile strength increased by 53%, and the mass loss decreased from 10.95 to 3.87%. Because the composites presented a considerable increase in mechanical properties, the modification of the conventional GIC with CNC can represent a new and promising dental restorative material. - Highlights: • Cellulose microfibers (CmF) and cellulose nanocrystals (CNC) were prepared. • The CmF and CNC were incorporated in commercial dental glass ionomer cement (GIC). • Small amount of CNC improved significantly all the mechanical properties evaluated. • Modified GIC with CNC can represent a new and promising dental restorative material.

  12. Commercialization of cellulose nanofibril (CNF) and cellulose nanocrystal (CNC): pathway and challenges

    Science.gov (United States)

    Alan Rudie

    2017-01-01

    The status of pilot-scale production methods for cellulose nanorods or nanocrystals and the 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-0xyl (TEMPO) grade of cellu— lose nanofibrils are discussed. Both products appear to be poised for scale-up when markets develop, but there are a number of issues that need to be addressed. This chapter outlines concepts for conversion...

  13. Understanding Plant Cellulose Synthases through a Comprehensive Investigation of the Cellulose Synthase Family Sequences.

    Science.gov (United States)

    Carroll, Andrew; Specht, Chelsea D

    2011-01-01

    The development of cellulose as an organizing structure in the plant cell wall was a key event in both the initial colonization and the subsequent domination of the terrestrial ecosystem by vascular plants. A wealth of experimental data has demonstrated the complicated genetic interactions required to form the large synthetic complex that synthesizes cellulose. However, these results are lacking an extensive analysis of the evolution, specialization, and regulation of the proteins that compose this complex. Here we perform an in-depth analysis of the sequences in the cellulose synthase (CesA) family. We investigate the phylogeny of the CesA family, with emphasis on evolutionary specialization. We define specialized clades and identify the class-specific regions within the CesA sequence that may explain this specialization. We investigate changes in regulation of CesAs by looking at the conservation of proposed phosphorylation sites. We investigate the conservation of sites where mutations have been documented that impair CesA function, and compare these sites to those observed in the closest cellulose synthase-like (Csl) families to better understand what regions may separate the CesAs from other Csls. Finally we identify two positions with strong conservation of the aromatic trait, but lacking conservation of amino acid identity, which may represent residues important for positioning the sugar substrate for catalysis. These analyses provide useful tools for understanding characterized mutations and post-translational modifications, and for informing further experiments to probe CesA assembly, regulation, and function through site-directed mutagenesis or domain swapping experiments.

  14. On the conflicting findings of Role of Cellulose-Crystallinity in Enzume Hydrolysis of Biomass

    Science.gov (United States)

    Umesh Agarwal; Sally Ralph

    2014-01-01

    In the field of conversion of biomass to ethanol, an important area of research is the enzymatic hydrolysis of cellulose. Once cellulose is converted to glucose, it can be easily fermented to ethanol. As the cellulosic ethanol technology stands now, costly pretreatments and high dosages of cellulases are needed to achieve complete hydrolysis of the cellulose fraction...

  15. Performance of cellulose derivatives in deep-fried battered snacks: Oil barrier and crispy properties

    NARCIS (Netherlands)

    Primo-Martín, C.; Sanz, T.; Steringa, D.W.; Salvador, A.; Fiszman, S.M.; Vliet, T. van

    2010-01-01

    The performance of batters containing cellulose derivatives (methyl cellulose (A4M), three hydroxypropylmethyl celluloses (E4M, F4M and K4M) with different degree of hydroxypropyl and/or methyl substitution and carboxymethyl cellulose (CMC)) to produce crispy deep-fried snacks crusts was studied by

  16. Elementary Particles

    Science.gov (United States)

    Parham, R.

    1974-01-01

    Presents the text of a speech given to a conference of physics teachers in which the full spectrum of elementary particles is given, along with their classification. Also includes some teaching materials available on this topic. (PEB)

  17. Hydrophobic cellulose films with excellent strength and toughness via ball milling activated acylation of microfibrillated cellulose.

    Science.gov (United States)

    Deng, Sha; Huang, Rui; Zhou, Mi; Chen, Feng; Fu, Qiang

    2016-12-10

    Cellulose films with excellent mechanical strength are of interest to many researchers, but unfortunately they often lack the ductility and water resistance. This work demonstrates an efficient and easily industrialized method for hydrophobic cellulose films made of modified microfibrillated cellulose (MFC). Prior to film fabrication, the simultaneous exfoliation and acylation of MFC was achieved through the synergetic effect of mechanical and chemical actions generated from ball milling in the presence of hexanoyl chloride. Largely enhanced tensile strength and elongation at break have been achieved (4.98MPa, 4.37% for original MFC films, 140MPa, 21.3% for modified ones). Due to hydrophobicity and compact structure, modified films show excellent water resistance and decreased water vapor permeability. Moreover, optical performance of modified films is also improved compared with the original MFC films. Our work can largely expand the application of this biodegradable resource and ultimately reduce the need for petroleum-based plastics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Morphological structure of Gluconacetobacter xylinus cellulose and cellulose-based organic-inorganic composite materials

    Science.gov (United States)

    Smyslov, R. Yu; Ezdakova, K. V.; Kopitsa, G. P.; Khripunov, A. K.; Bugrov, A. N.; Tkachenko, A. A.; Angelov, B.; Pipich, V.; Szekely, N. K.; Baranchikov, A. E.; Latysheva, E.; Chetverikov, Yu O.; Haramus, V.

    2017-05-01

    Scanning electron microscopy, ultra-small-angle neutron scattering (USANS), small-angle neutron and X-ray scattering (SANS and SAXS), as well as low-temperature nitrogen adsorption, were used in the studies of micro- and mesostructure of polymer matrix prepared from air-dry preliminarily disintegrated cellulose nano-gel film (synthesized by Gluconacetobacter xylinus) and the composites based on this bacterial cellulose. The composites included ZrO2 nanoparticles, Tb3+ in the form of low molecular weight salt and of metal-polymer complex with poly(vinylpyrrolydone)-poly(methacryloyl-o-aminobenzoic acid) copolymer. The combined analysis of the data obtained allowed revealing three levels of fractal organization in mesostructure of G. xylinus cellulose and its composites. It was shown that both the composition and an aggregation state of dopants have a significant impact on the structural characteristics of the organic-inorganic composites. The composites containing Tb3+ ions demonstrate efficient luminescence; its intensity is an order of magnitude higher in the case of the composites with the metal-polymer complex. It was found that there is the optimal content of ZrO2 nanoparticles in composites resulting in increased Tb3+ luminescence.

  19. Effect of Cellulose Nanocrystals and Bacterial Cellulose on Disintegrability in Composting Conditions of Plasticized PHB Nanocomposites

    Directory of Open Access Journals (Sweden)

    Irene Teresita Seoane

    2017-10-01

    Full Text Available Poly(hydroxybutyrate (PHB-based films, reinforced with bacterial cellulose (BC or cellulose nanocrystals (CNC and plasticized using a molecular (tributyrin or a polymeric plasticizer (poly(adipate diethylene, were produced by solvent casting. Their morphological, thermal, wettability, and chemical properties were investigated. Furthermore, the effect of adding both plasticizers (20 wt % respect to the PHB content and biobased selected nanofillers added at different contents (2 and 4 wt % on disintegrability in composting conditions was studied. Results of contact angle measurements and calorimetric analysis validated the observed behavior during composting experiments, indicating how CNC aggregation, due to the hydrophilic nature of the filler, slows down the degradation rate but accelerates it in case of increasing content. In contrast, nanocomposites with BC presented an evolution in composting similar to neat PHB, possibly due to the lower hydrophilic character of this material. The addition of the two plasticizers contributed to a better dispersion of the nanoparticles by increasing the interaction between the cellulosic reinforcements and the matrix, whereas the increased crystallinity of the incubated samples in a second stage in composting provoked a reduction in the disintegration rate.

  20. Morphological structure of Gluconacetobacter xylinus cellulose and cellulose-based organic-inorganic composite materials

    International Nuclear Information System (INIS)

    Yu Smyslov, R; Khripunov, A K; Bugrov, A N; Ezdakova, K V; Kopitsa, G P; Chetverikov, Yu O; Tkachenko, A A; Angelov, B; Pipich, V; Szekely, N K; Baranchikov, A E; Latysheva, E; Haramus, V

    2017-01-01

    Scanning electron microscopy, ultra-small-angle neutron scattering (USANS), small-angle neutron and X-ray scattering (SANS and SAXS), as well as low-temperature nitrogen adsorption, were used in the studies of micro- and mesostructure of polymer matrix prepared from air-dry preliminarily disintegrated cellulose nano-gel film (synthesized by Gluconacetobacter xylinus ) and the composites based on this bacterial cellulose. The composites included ZrO 2 nanoparticles, Tb 3+ in the form of low molecular weight salt and of metal-polymer complex with poly(vinylpyrrolydone)-poly(methacryloyl- o -aminobenzoic acid) copolymer. The combined analysis of the data obtained allowed revealing three levels of fractal organization in mesostructure of G. xylinus cellulose and its composites. It was shown that both the composition and an aggregation state of dopants have a significant impact on the structural characteristics of the organic-inorganic composites. The composites containing Tb 3+ ions demonstrate efficient luminescence; its intensity is an order of magnitude higher in the case of the composites with the metal-polymer complex. It was found that there is the optimal content of ZrO 2 nanoparticles in composites resulting in increased Tb 3+ luminescence. (paper)

  1. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

    Energy Technology Data Exchange (ETDEWEB)

    Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J., E-mail: rosemarymj@lifecarehll.com

    2016-04-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

  2. Cellulose nanowhiskers and nanofibers from biomass for composite applications

    Science.gov (United States)

    Wang, Tao

    2011-12-01

    Biological nanocomposites such as plant cell wall exhibit high mechanical properties at a light weight. The secret of the rigidity and strength of the cell wall lies in its main structural component -- cellulose. Native cellulose exists as highly-ordered microfibrils, which are just a few nanometers wide and have been found to be stiffer than many synthetic fibers. In the quest for sustainable development around the world, using cellulose microfibrils from plant materials as renewable alternatives to conventional reinforcement materials such as glass fibers and carbon fibers is generating particular interest. In this research, by mechanical disintegration and by controlled chemical hydrolysis, both cellulose nanofibers and nanowhiskers were extracted from the cell wall of an agricultural waste, wheat straw. The reinforcement performances of the two nanofillers were then studied and compared using the water-soluble polyvinyl alcohol (PVOH) as a matrix material. It was found that while both of these nanofillers could impart higher stiffness to the polymer, the nanofibers from biomass were more effective in composite reinforcement than the cellulose crystals thanks to their large aspect ratio and their ability to form interconnected network structures through hydrogen bonding. One of the biggest challenges in the development of cellulose nanocomposites is achieving good dispersion. Because of the high density of hydroxyl groups on the surface of cellulose, it remains a difficult task to disperse cellulose nanofibers in many commonly used polymer matrices. The present work addresses this issue by developing a water-based route taking advantage of polymer colloidal suspensions. Combining cellulose nanofibers with one of the most important biopolymers, poly(lactic acid) (PLA), we have prepared nanocomposites with excellent fiber dispersion and improved modulus and strength. The bio-based nanocomposites have a great potential to serve as light-weight structural materials

  3. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

    International Nuclear Information System (INIS)

    Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J.

    2016-01-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

  4. Particle detectors

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The lecture series will present an overview of the basic techniques and underlying physical principles of particle detectors, applied to current and future high energy physics experiments. Illustrating examples, mainly from the field of collider experiments, will demonstrate the performance and limitations of the various techniques. After an introduction the following topics will be covered: Tracking (gas, solid state based) - Scintillation and light detection Calorimetry - Particle Identification - Electronics and Data Acquisition - Detector Systems

  5. Auroral particles

    Science.gov (United States)

    Evans, David S.

    1987-01-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries.

  6. Plasma electrolytic liquefaction of cellulosic biomass

    Science.gov (United States)

    Dingliang, TANG; Xianhui, ZHANG; Si-ze, YANG

    2018-04-01

    In this paper, the rapid liquefaction of a corncob was achieved by plasma electrolysis, providing a new method for cellulosic biomass liquefaction. The liquefaction rate of the corncob was 95% after 5 min with polyethylene glycol and glycerol as the liquefying agent. The experiments not only showed that H+ ions catalyzed the liquefaction of the corncob, but also that using accelerated H+ ions, which were accelerated by an electric field, could effectively improve the liquefaction efficiency. There was an obvious discharge phenomenon, in which the generated radicals efficiently heated the solution and liquefied the biomass, in the process of plasma electrolytic liquefaction. Finally, the optimum parameters of the corncob liquefaction were obtained by experimentation, and the liquefaction products were analyzed.

  7. Capillary rise and swelling in cellulose sponges

    Science.gov (United States)

    Ha, Jonghyun; Kim, Jungchul; Kim, Ho-Young

    2015-11-01

    A cellulose sponge, which is a mundane example of a porous hydrophilic structure, can absorb and hold a significant amount of liquid. We present the results of experimental and theoretical investigation of the dynamics of the capillary imbibition of various aqueous solutions in the sponge that swells at the same time. We find that the rate of water rise against the resistance caused by gravitational and viscous effects deviates from Washburn's rule beyond a certain threshold height. We rationalize the novel power law of the rise height versus time by combining Darcy's law with hygroscopic swelling equation and also predict the threshold height. The scaling law constructed through this work agrees well with the experimental results, shedding light on the physics of capillary flow in deforming porous media.

  8. Novel enzymes for the degradation of cellulose

    Directory of Open Access Journals (Sweden)

    Horn Svein

    2012-07-01

    Full Text Available Abstract The bulk terrestrial biomass resource in a future bio-economy will be lignocellulosic biomass, which is recalcitrant and challenging to process. Enzymatic conversion of polysaccharides in the lignocellulosic biomass will be a key technology in future biorefineries and this technology is currently the subject of intensive research. We describe recent developments in enzyme technology for conversion of cellulose, the most abundant, homogeneous and recalcitrant polysaccharide in lignocellulosic biomass. In particular, we focus on a recently discovered new type of enzymes currently classified as CBM33 and GH61 that catalyze oxidative cleavage of polysaccharides. These enzymes promote the efficiency of classical hydrolytic enzymes (cellulases by acting on the surfaces of the insoluble substrate, where they introduce chain breaks in the polysaccharide chains, without the need of first “extracting” these chains from their crystalline matrix.

  9. Study on stimulus-responsive cellulose-based polymeric materials

    Science.gov (United States)

    Luo, Hongsheng

    Stimulus-responsive cellulose-based polymeric materials were developed by physical and chemical approaches. The thermal, structural, mechanical and morphological properties of the samples were comprehensively investigated by multiple tools. Shape memory effect (SME), programming-structure-property relationship and underling mechanisms were emphasized in this study. Some new concepts, such as heterogeneous-twin-switch, path-dependent multi-shape, rapidly switchable water-sensitive SME were established. The samples were divided into two categories. For the first category, cellulose nano-whiskers (CNWs) were incorporated into crystalline shape memory polyurethane (SMPU) and thermal plastic polyurethane (TPU). The CNW-SMPU nano-composites had heterogeneous switches. Triple- and multi-shape effects were achieved for the CNW-SMPU nano-composites by applying into appropriate thermal-aqueous-mechanical programming. Furthermore, the thermally triggered shape recovery of the composites was found to be tuneable, depending on the PCN content. Theoretical prediction along with numerical analysis was conducted, providing evidence on the possible microstructure of the CNW-SMPU nano-composites. Rapidly switchable water-sensitive SME of the CNW-TPU nano-composites was unprecedentedly studied, which originated from the reversible regulation of hydrogen bonding by water. The samples in the second category consisted of cellulose-polyurethane (PU) blends, cellulose-poly(acrylic acid) (PAA) composites and modified cellulose with supramolecular switches, featuring the requirement of homogeneous cellulose solution in the synthesis process. The reversible behaviours of the cellulose-PU blends in wet-dry cycles as well as the underlying shape memory mechanism were characterized and disclosed. The micro-patterns of the blends were found to be self-similar in fractal dimensions. Cellulose-PAA semi-interpenetrating networks exhibited mechanical adaptability in wet-dry cycles. A type of

  10. Cellulose Electro-Active Paper: From Discovery to Technology Applications

    Directory of Open Access Journals (Sweden)

    Zafar eAbas

    2014-09-01

    Full Text Available Cellulose electro-active paper (EAPap is an attractive material of electro-active polymers (EAPs family due to its smart characteristics. EAPap is thin cellulose film coated with metal electrodes on both sides. Its large displacement output, low actuation voltage and low power consumption can be used for biomimetic sensors/actuators and electromechanical system. Because cellulose EAPap is ultra-lightweight, easy to manufacture, inexpensive, biocompatible, and biodegradable, it has been employed for many applications such as bending actuator, vibration sensor, artificial muscle, flexible speaker, and can be advantageous in areas such as micro-insect robots, micro-flying objects, microelectromechanical systems, biosensors, and flexible displays.

  11. Sustainable green composites of thermoplastic starch and cellulose fibers

    Directory of Open Access Journals (Sweden)

    Amnuay Wattanakornsiri

    2014-04-01

    Full Text Available Green composites have gained renewed interest as environmental friendly materials and as biodegradable renewable resources for a sustainable development. This review provides an overview of recent advances in green composites based on thermoplastic starch (TPS and cellulose fibers. It includes information about compositions, preparations, and properties of starch, cellulose fibers, TPS, and green composites based on TPS and cellulose fibers. Introduction and production of these recyclable composites into the material market would be important for environmental sustainability as their use can decrease the volume of petroleum derived plastic waste dumps. Green composites are comparable cheap and abundant, but further research and development is needed for a broader utilization.

  12. Cellulose-containing Waste and Bituminized Salts

    International Nuclear Information System (INIS)

    Valcke, E.

    2005-01-01

    In Belgium, Medium-Level radioactive Waste (MLW) would be eventually disposed off in an underground repository in a geological formation such as the Boom Clay, which is studied as a reference host rock formation. MLW contains large quantities of non-radioactive chemicals that are released upon contact with pore water. It could be the case, for instance, for plutonium bearing cellulosic waste - such as paper tissues used to clean alpha glove boxes - issued from nuclear fuel fabrication (Belgonucleaire). At high pH, as in a disposal gallery backfilled with cement, the chemical degradation of cellulose will generate water-soluble products that may form strong complexes with actinides such as Am, Pu, Np, and U. This could lower the sorption of these elements onto the clay minerals, and hence increase their migration through the clay barrier. Another chemical perturbation could occur from the 3000 m 3 of so-called Eurobitum bituminised MLW, with precipitation sludges from the chemical treatment of spent nuclear fuel, and containing about 750 tons of NaNO 3 . The presence of NaNO 3 in this waste will give rise to several processes susceptible to affect the safety of the disposal system. Amongst others, it is necessary to verify that the swelling pressure of bitumen on the gallery wall and the osmotic pressure within the near-field are not too high to induce a fissuration of the host rock, leading to the formation of preferential migration pathways. The major objective of our work is to obtain a broad understanding of the different processes induced by the release of non-radioactive chemicals in the clay formation, to assess the chemical compatibility of different MLW forms with the clay

  13. Simple approach to reinforce hydrogels with cellulose nanocrystals

    Science.gov (United States)

    Yang, Jun; Han, Chun-Rui; Xu, Feng; Sun, Run-Cang

    2014-05-01

    The physical crosslinking of colloidal nanoparticles via dynamic and directional non-covalent interactions has led to significant advances in composite hydrogels. In this paper, we report a simple approach to fabricate tough, stretchable and hysteretic isotropic nanocomposite hydrogels, where rod-like cellulose nanocrystals (CNCs) are encapsulated by flexible polymer chains of poly(N,N-dimethylacrylamide) (PDMA). The CNC-PDMA colloidal clusters build a homogeneously cross-linked network and lead to significant reinforcing effect of the composites. Hierarchically structured CNC-PDMA clusters, from isolated particles to an interpenetrated network, are observed by transmission electron microscopy measurements. Dynamic shear oscillation measurements are applied to demystify the differences in network rheological behaviors, which were compared with network behaviors of chemically cross-linked PDMA counterparts. Tensile tests indicate that the hybrid hydrogels possess higher mechanical properties and a more efficient energy dissipation mechanism. In particular, with only 0.8 wt% of CNC loading, a 4.8-fold increase in Young's modulus, 9.2-fold increase in tensile strength, and 5.8-fold increase in fracture strain are achieved, which is ascribed to a combination of CNC reinforcement in the soft matrix and CNC-PDMA colloidal cluster conformational rearrangement under stretching. Physical interactions within networks serve as reversible sacrificial bonds that dissociate upon deformation, exhibiting large hysteresis as an energy dissipation mechanism via cluster mobility. This result contrasts with the case of chemically cross-linked PDMA counterparts where the stress relaxation is slow due to the permanent cross-links and low resistance against crack propagation within the covalent network.The physical crosslinking of colloidal nanoparticles via dynamic and directional non-covalent interactions has led to significant advances in composite hydrogels. In this paper, we report

  14. Study Adsorption Desorption of Manganese(ii) Using Impregnated Chitin-cellulose as Adsorbent

    OpenAIRE

    Lesbani, Aldes; Turnip, Ema Veronika; Mohadi, Risfidian; Hidayati, Nurlisa

    2015-01-01

    - Study adsorption desorption of manganese(II) using impregnated chitin-cellulose as adsorbent has been carried out. Chitin was extracted from snail shell and cellulose isolated from rice straw. Chitin and cellulose were impregnated using thiourea as impregnant agent. Characterization of chitin and cellulose was performed using FTIR spectroscopy, determination of water content, and ash content, while impregnated chitin-cellulose was characterized using FTIR spectrophotometer and X-Ray diffrac...

  15. Determination of the size and phase composition of silver nanoparticles in a gel film of bacterial cellulose by small-angle X-ray scattering, electron diffraction, and electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, V. V.; Klechkovskaya, V. V., E-mail: klechvv@ns.crys.ras.ru; Shtykova, E. V.; Dembo, K. A.; Arkharova, N. A.; Ivakin, G. I. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Smyslov, R. Yu. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation)

    2009-03-15

    The nanoscale structural features in a composite (gel film of Acetobacter Xylinum cellulose with adsorbed silver nanoparticles, stabilized by N-polyvinylpyrrolidone) have been investigated by small-angle X-ray scattering. The size distributions of inhomogeneities in the porous structure of the cellulose matrix and the size distributions of silver nanoparticles in the composite have been determined. It is shown that the sizes of synthesized nanoparticles correlate with the sizes of inhomogeneities in the gel film. Particles of larger size (with radii up to 100 nm) have also been found. Electron microscopy of thin cross sections of a dried composite layer showed that large particles are located on the cellulose layer surface. Electron diffraction revealed a crystal structure of silver nanoparticles in the composite.

  16. Cement Materials Based on Cellulosic Fibers for Plasters

    Science.gov (United States)

    Hospodarova, Viola; Stevulova, Nadezda; Junak, Jozef; Geffert, Anton; Kacik, Frantisek; Briancin, Jaroslav

    2017-06-01

    This paper presents physical and mechanical properties of cementitious composites/plasters containing cellulosic fibers in portion 2.0% and 5.0% of filler replacement after 28 days of hardening. Cellulosic fibers (Greencel) originated from bleached wood pulp and unbleached waste paper used in this experimental work were characterized from the point of view cellulose structure. Experimental investigations reveal that adding cellulosic fibers reduces composites density (up to 8.2 %) in comparison with composites without any fibers. Moreover, the presence of wood pulp and recycled fibers in composites cause higher values of water absorbability than sample without fibers. Also, the decrease in compressive strength values for tested fiber cement plasters was observed (14.1 - 18.0 MPa) in comparison to reference sample (26.6 MPa). But the identified compressive strength values are in accordance with European standard (5 MPa) for plasters.

  17. Cement Materials Based on Cellulosic Fibers for Plasters

    Directory of Open Access Journals (Sweden)

    Hospodarova Viola

    2017-06-01

    Full Text Available This paper presents physical and mechanical properties of cementitious composites/plasters containing cellulosic fibers in portion 2.0% and 5.0% of filler replacement after 28 days of hardening. Cellulosic fibers (Greencel originated from bleached wood pulp and unbleached waste paper used in this experimental work were characterized from the point of view cellulose structure. Experimental investigations reveal that adding cellulosic fibers reduces composites density (up to 8.2 % in comparison with composites without any fibers. Moreover, the presence of wood pulp and recycled fibers in composites cause higher values of water absorbability than sample without fibers. Also, the decrease in compressive strength values for tested fiber cement plasters was observed (14.1 - 18.0 MPa in comparison to reference sample (26.6 MPa. But the identified compressive strength values are in accordance with European standard (5 MPa for plasters.

  18. Microfibrillated cellulose and new nanocomposite materials: a review

    DEFF Research Database (Denmark)

    Siró, Istvan; Plackett, David

    2010-01-01

    Due to their abundance, high strength and stiffness, low weight and biodegradability, nano-scale cellulose fiber materials (e.g., microfibrillated cellulose and bacterial cellulose) serve as promising candidates for bio-nanocomposite production. Such new high-value materials are the subject...... typically required high energy input, chemical and/or enzymatic fiber pre-treatments have been developed to overcome this problem. A challenge associated with using nanocellulose in composites is the lack of compatibility with hydrophobic polymers and various chemical modification methods have been explored...... in order to address this hurdle. This review summarizes progress in nanocellulose preparation with a particular focus on microfibrillated cellulose and also discusses recent developments in bio-nanocomposite fabrication based on nanocellulose....

  19. Modification and characterization of microcrystalline cellulose with succinic anhydride

    International Nuclear Information System (INIS)

    Santos, Clecio M.R.; Santos, Douglas C.; Freitas, Gizele B.; Cardoso, Giselia

    2011-01-01

    Cellulose is a natural polymer, non-toxic, biodegradable and renewable source. With increasing global attention to environmental problems, the chemical modification of cellulose has been evaluated with increasing applicability in various industrial sectors. The cellulose can be chemical modified through the hydroxyl present in their molecules. This paper aims to present the main results in the modification of microcrystalline cellulose. The sample was pure and modified chemically and morphologically characterized by absorption spectroscopy in the infrared (IR) and showed the band in the 1551cm -1 characterization modification made, X-ray diffraction (XRD) where it was observed that the change led to a reduction significant crystallinity, and determination of average pore radius through the analyzer porosity and surface area resulting in values of 6.97 angstrom for pure sample and 8.62 angstrom for the modified. In addition to these tests we determined the average degree of substitution finding the value of 1.67. (author)

  20. Polyvinyl alcohol–cellulose composite: a taste sensing material

    Indian Academy of Sciences (India)

    Unknown

    cellulose composite membrane was converted to phosphate ester by phosphorylation, phosphorus content of the membrane was estimated by Heraeus Schöniger Combustion Appa- ratus, Germany, following the method of Schöniger (1955).

  1. Macromolecular organization of xyloglucan and cellulose in pea epicotyls

    International Nuclear Information System (INIS)

    Hayashi, T.; Maclachlan, G.

    1984-01-01

    Xyloglucan is known to occur widely in the primary cell walls of higher plants. This polysaccharide in most dicots possesses a cellulose-like main chain with three of every four consecutive residues substituted with xylose and minor addition of other sugars. Xyloglucan and cellulose metabolism is regulated by different processes; since different enzyme systems are probably required for the synthesis of their 1,4-β-linkages. A macromolecular complex composed of xyloglucan and cellulose only was obtained from elongating regions of etiolated pea stems. It was examined by light microscopy using iodine staining, by radioautography after labeling with [ 3 H]fructose, by fluorescence microscopy using a fluorescein-lectin (fructose-binding) as probe, and by electron microscopy after shadowing. The techniques all demonstrated that the macromolecule was present in files of cell shapes, referred to here as cell-wall ghosts, in which xyloglucan was localized both on and between the cellulose microfibrils

  2. Natural Composites: Cellulose Fibres and the related Performance of Composites

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2014-01-01

    Biobased materials are becoming of increasing interest as potential structural materials for the future. A useful concept in this context is the fibre reinforcement of materials by stiff and strong fibres. The biobased resources can contribute with cellulose fibres and biopolymers. This offers...... the potential for stiff and strong biocomposite materials, but these have some limitations and obstacles to full performance. The focus will be on the ultra-structure, and the strength and stiffness of cellulose fibres, on the (unavoidable) defects causing large reductions in strength and moderate reductions...... in stiffness, on the packing ability of cellulose fibres and the related maximum fibre volume fraction in composites, on the moisture sorption of cellulose fibres and the related mass increase and (large) hygral strains induced, and on the mechanical performance of composites....

  3. Study of "napier grass" delignification for production of cellulosic derivatives.

    Science.gov (United States)

    de Araújo Morandim-Giannetti, Andreia; Albuquerque, Tiago Santos; de Carvalho, Renata Kobal Campos; Araújo, Ramires Menezes Silva; Magnabosco, Rodrigo

    2013-01-30

    Recently, much research on the evaluation of new cellulose sources has been developed. In this context, a promising source is "napier grass", which contains 30.40% lignin, 36.34% cellulose, and 34.12% hemicellulose. In this work, conditions for the delignification of "napier grass" in the laboratory were studied by using calcium oxide (CaO) and hydrogen peroxide (H(2)O(2)). The best pulping conditions were 9.00% CaO for a period of 2.73 h, which resulted in 74.99% delignification and 66.58% cellulose. The best conditions for the bleaching process were pH 12 and hydrogen peroxide at concentration of 4.2% for 6h, at a temperature of 40 °C, which gave 90.98% delignification and 99.21% cellulose. The analyses were performed by using weight percent. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Alternative fuels from waste cellulosic substrates and poly furfuryl alcohol

    CSIR Research Space (South Africa)

    Kumar, R

    2012-03-01

    Full Text Available This paper provides methods for manufacturing alternative fuels from waste cellulosic substrates reinforced by poly furfuryl alcohol (PFA). PFA, as a matrix, is obtained from the condensation polymerization of furfuryl alcohol – a waste of sugarcane...

  5. Biodegradable Cellulose-based Hydrogels: Design and Applications

    Science.gov (United States)

    Sannino, Alessandro; Demitri, Christian; Madaghiele, Marta

    2009-01-01

    Hydrogels are macromolecular networks able to absorb and release water solutions in a reversible manner, in response to specific environmental stimuli. Such stimuli-sensitive behaviour makes hydrogels appealing for the design of ‘smart’ devices, applicable in a variety of technological fields. In particular, in cases where either ecological or biocompatibility issues are concerned, the biodegradability of the hydrogel network, together with the control of the degradation rate, may provide additional value to the developed device. This review surveys the design and the applications of cellulose-based hydrogels, which are extensively investigated due to the large availability of cellulose in nature, the intrinsic degradability of cellulose and the smart behaviour displayed by some cellulose derivatives.

  6. Biodegradable Cellulose-based Hydrogels: Design and Applications

    Directory of Open Access Journals (Sweden)

    Marta Madaghiele

    2009-04-01

    Full Text Available Hydrogels are macromolecular networks able to absorb and release water solutions in a reversible manner, in response to specific environmental stimuli. Such stimuli-sensitive behaviour makes hydrogels appealing for the design of ‘smart’ devices, applicable in a variety of technological fields. In particular, in cases where either ecological or biocompatibility issues are concerned, the biodegradability of the hydrogel network, together with the control of the degradation rate, may provide additional value to the developed device. This review surveys the design and the applications of cellulose-based hydrogels, which are extensively investigated due to the large availability of cellulose in nature, the intrinsic degradability of cellulose and the smart behaviour displayed by some cellulose derivatives.

  7. Particle detectors

    CERN Document Server

    AUTHOR|(CDS)2068232

    1998-01-01

    The lecture series will present and overview of the basic techniques and underlying physical principles of particle detectors, applied to current and future high energy physics experiments. Illustrating examples, mainly from the field of collider experiments, will demonstrate the performance and limitations of the various techniques. After and introduction we shall concentrate on particle tracking. Wire chambers, drift chambers, micro gaseous tracking devices and solid state trackers will be discussed. It follows and overview of scintillators, photon detection, fiber tracking and nuclear emulsions. One lecture will deal with the various techniques of calorimetry. Finally we shall focus on methods developed for particle identification. These comprise specific energy loss, time of flight Cherenkov and transition radiation detectors.

  8. Particle detectors

    CERN Document Server

    Hilke, Hans Jürgen; Joram, Christian; CERN. Geneva

    1991-01-01

    Lecture 5: Detector characteristics: ALEPH Experiment cut through the devices and events - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operartion and a few ideas on the future performance. Lecture 4-pt. b Following the Scintillators. Lecture 4-pt. a : Scintillators - Used for: -Timing (TOF, Trigger) - Energy Measurement (Calorimeters) - Tracking (Fibres) Basic scintillation processes- Inorganic Scintillators - Organic Scintil - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operation and a fiew ideas on future developpement session 3 - part. b Following Calorimeters lecture 3-pt. a Calorimeters - determine energy E by total absorption of charged or neutral particles - fraction of E is transformed into measurable quantities - try to acheive sig...

  9. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  10. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  11. Primary radiation defect production in polyethylene and cellulose.

    Science.gov (United States)

    Polvi, Jussi; Luukkonen, Petri; Nordlund, Kai; Järvi, Tommi T; Kemper, Travis W; Sinnott, Susan B

    2012-11-29

    Irradiation effects in polyethylene and cellulose were examined using molecular dynamics simulations. The governing reactions in both materials were chain scissioning and generation of small hydrocarbon and peroxy radicals. Recombination of chain fragments and cross-linking between polymer chains were found to occur less frequently. Crystalline cellulose was found to be more resistant to radiation damage than crystalline polyethylene. Statistics on radical formation are presented and the dynamics of the formation of radiation damage discussed.

  12. Synthesis and Applications of Cellulose Derivatives for Drug Delivery

    Science.gov (United States)

    Marks, Joyann Audrene

    In an effort to produce new derivatives of cellulose for drug delivery applications, methods were developed to regioselectively modify C-6 halo cellulose esters to produce cationic derivatives via nucleophilic substitution. Reaction of C-6 substituted bromo and iodo cellulose with trialkylated amines and phosphines produced new cationic ammonium and phosphonium cellulose derivatives which can be explored as delivery agents for nucleic acids, proteins and other anionic drug molecules. It was anticipated that these new derivatives would not only be capable of complexing anionic drug molecules but would have greatly improved aqueous solubility compared to their precursors. The phosphonium derivatives described in this work are an obvious example of such improved solubility properties. Given the importance of cellulose derivatives in making amorphous dispersions with critical drugs, it has also been important to analyze commercially available polymers for the potential impact in oral drug delivery formulations. To do so pairwise blends of cellulosics and synthetic polymers commonly used as excipients were tested for miscibility using techniques such as DSC, mDSC, FTIR and film clarity. Miscible combinations highlight the potential to use combinations of polymers currently available commercially to provide drug delivery solutions for specific drug formulations. The use of melt extrusion in processing some of these drug/polymer dispersions provides a means of highlighting the capability for the use of these cellulosics in melt extruded amorphous dispersions. This solvent free, high pressure method significantly reduces cost and time and can be applied on a large scale. The analysis of long chain cellulose esters and ultimately the novel omega carboxy esters for melt processability significantly impacts the possibilities available for use of those excellent drug delivery agents on a much larger scale.

  13. Recent Development in Spectroscopic and Chemical Characterization of Cellulose

    Science.gov (United States)

    2005-01-01

    degraded to hydroxymethylfur- fural, levulinic acid , formic acid , and others during acid hydrolysis (Fig. 22). B. Enzymatic Degradation Cellulase...prepared from cotton linters by acid hydrolysis (c), a low-DP regenerated cellu- lose I (d), cellulose from Acetobucter xylinum (e), and cellulose...little difference in the essential features of the spectra, even after the samples had been subjected to acid hydrolysis. Furthermore, it was concluded

  14. Chemical Compounds Recovery in Carboxymethyl Cellulose Wastewater Treatment

    OpenAIRE

    P.-H. Rao; W.-Q. Zhang; W. Yao; A.-Y. Zhu; J.-L. Xia; Y.-F. Tan; T.-Z. Liu

    2015-01-01

    Carboxymethyl cellulose (CMC) is a kind of cellulose ether widely used in industrial production. CMC wastewater usually have high chemical oxygen demand (COD) and salinity (>10 %), which result from organic and inorganic by-products during CMC production. It is significant that the wastewater is pretreated to decrease salinity and recover valuable organics before biochemical methods are employed. In this paper, distillation-extraction method was used to pretreat CMC wastewater and recover val...

  15. Preparation and characterization of gelatin scaffold containing microorganism fermented cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Mook; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang; Lee, Byeong Heon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Mi Yeong; Lee, Jong Dae; Song, Sung Gi [Quegenbiotech, Co., Incheon (Korea, Republic of)

    2010-12-15

    Cellulose, chitin, chitosan and hyaluronic acid are well known as polysaccharides. These polysaccharides have many effects on cell growth and differentiation. Cell activation increases with increasing the polysaccharides concentration. In this study, gelatin scaffold containing microorganism fermented cellulose, citrus gel were prepared by using irradiation technique. Physical properties of the scaffolds were investigated as a function of the concentrations of gelatin and citrus gel and the cell attachment, cell morphology and inflammation of the scaffolds also were characterized for regeneration of skin tissue.

  16. Cellulose and polypropylene filament for 3D printing

    OpenAIRE

    Kwan, Isabella

    2016-01-01

    Additive manufacturing has become a very popular and well mentioned technique in recent years. The technique, where 3 dimensional (3D) printing is included, creates opportunities to develop new designs and processing systems. As a research institute within the forest based processes and products, Innventia AB has an idea of combining 3D printing with cellulose. The addition of cellulose will increase the proportion of renewable raw material contributing to more sustainable products. However, ...

  17. Particle physics

    CERN Document Server

    Martin, Brian R

    2017-01-01

    An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.

  18. Fabrication and characterization of novel biomimetic PLLA/cellulose/hydroxyapatite nanocomposite for bone repair applications

    Energy Technology Data Exchange (ETDEWEB)

    Eftekhari, Samin [Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada); El Sawi, Ihab; Bagheri, Zahra Shaghayegh [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada); Turcotte, Ginette [Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada); Bougherara, Habiba, E-mail: habiba.bougherara@ryerson.ca [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada)

    2014-06-01

    The purpose of this research is to develop and characterize a novel biomimetic nanocomposite that closely mimics the properties of real bone such as morphology, composition and mechanical characteristics. This novel porous nanocomposite is composed of cotton-sourced cellulose microcrystals, hydroxyapatite nanoparticles and poly L-lactide acid. A unique combination of commonly used fabrication procedures has been developed including pre-treatment of particles using a coupling agent. The effect of various weight ratios of the reinforcing agents was evaluated to assess their influence on the chemical, thermal, and mechanical properties of the nanocomposites. The prepared nanocomposites were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and compression testing. Our results indicated the presence of molecular interactions between all components leading to an increase of the crystallinity of the polymer from 50% to 80%. Compression test results revealed that increasing the weight ratio of microcrystalline cellulose/poly L-lactide acid and hydroxyapatite/poly L-lactide acid from 0.1 to 0.5 enhanced the compressive yield stress from 0.127 to 2.2 MPa and The Young's modulus from 6.6 to 38 MPa, respectively. It was found that the fabricated nanocomposites are comparable with the trabecular bone from compositional, structural, and mechanical point of view. - Highlights: • Fabrication of PLLA/HA/cellulose composites that mimic the spongeous bone • Homogenous dispersion of the reinforcing agents in the PLLA matrix was attained. • More efficient interface between the PLLA and the reinforcing agents was achieved. • Preliminary in vitro biocompatibility test showed the nontoxicity of the composite. • The crystallinity, the compressive strength and modulus were investigated.

  19. Cellulose fermentation by nitrogen-fixing anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Canale-Parola, E.

    1992-12-13

    In anaerobic natural environments cellulose is degraded to methane, carbon dioxide and other products by the combined activities of many diverse microorganisms. We are simulating processes occurring in natural environments by constructing biologically-defined, stable, heterogeneous bacterial communities (consortia) that we use as in vitro systems for quantitative studies of cellulose degradation under conditions of combined nitrogen deprivation. These studies include the investigation of (i) metabolic interactions among members of cellulose-degrading microbial populations, and (ii) processes that regulate the activity or biosynthesis of cellulolytic enzymes. In addition, we are studying the sensory mechanisms that, in natural environments, may enable motile cellulolytic bacteria to migrate toward cellulose. This part of our work includes biochemical characterization of the cellobiose chemoreceptor of cellulolytic bacteria. Finally, an important aspect of our research is the investigation of the mechanisms by which multienzyme complexes of anaerobic bacteria catalyze the depolymerization of crystalline cellulose and of other plant cell wall polysacchaddes. The research will provide fundamental information on the physiology and ecology of cellulose-fermenting, N{sub 2}-fixing bacteria, and on the intricate processes involved in C and N cycling in anaerobic environments. Furthermore, the information will be valuable for the development of practical applications, such as the conversion of plant biomass (e.g., agricultural, forestry and municipal wastes) to automotive fuels such as ethanol.

  20. Antibacterial Activity of Nanocomposites of Copper and Cellulose

    Directory of Open Access Journals (Sweden)

    Ricardo J. B. Pinto

    2013-01-01

    Full Text Available The design of cheap and safe antibacterial materials for widespread use has been a challenge in materials science. The use of copper nanostructures combined with abundant biopolymers such as cellulose offers a potential approach to achieve such materials though this has been less investigated as compared to other composites. Here, nanocomposites comprising copper nanofillers in cellulose matrices have been prepared by in situ and ex situ methods. Two cellulose matrices (vegetable and bacterial were investigated together with morphological distinct copper particulates (nanoparticles and nanowires. A study on the antibacterial activity of these nanocomposites was carried out for Staphylococcus aureus and Klebsiella pneumoniae, as pathogen microorganisms. The results showed that the chemical nature and morphology of the nanofillers have great effect on the antibacterial activity, with an increase in the antibacterial activity with increasing copper content in the composites. The cellulosic matrices also show an effect on the antibacterial efficiency of the nanocomposites, with vegetal cellulose fibers acting as the most effective substrate. Regarding the results obtained, we anticipate the development of new approaches to prepare cellulose/copper based nanocomposites thereby producing a wide range of interesting antibacterial materials with potential use in diverse applications such as packaging or paper coatings.